Interesting thread. Another issue, what about parking at your destination outside in very low temperature? Trying to get home when the aircraft has been outside a couple days in 0 - -20 degrees. Might lead to lots of preparations depending of how cold it is. Possible dead battery etc... I would be more comfortable going places in winter if i could park in a hangar. Any experience of this?
If your battery goes belly-up from couple of nights in light sub-zero temperatures then you simply need a new battery.
Frost (or even ice and snow) on the aircraft surfaces can be a problem. I just recently experienced some frost the morning of my departure from Lviv. I was lucky to have a jug of TKS fluid in my baggage compartment, which helped a lot.
In most of the bigger airports, it is not possible to get hangarage as a visitor, and if you can, it is often super-expensive.
However, as Peter said, most private pleasure flyers usually don't do many overnight flying trips to destinations with freezing-temperature (maybe with exception of the odd ski-trip, but I have never done any).
what about parking at your destination outside in very low temperature? Trying to get home when the aircraft has been outside a couple days in 0 - -20 degrees.
I have done this many times now. In some places hangarage is available - price can vary a lot but is cheaper than commercial deicing. Never had battery problems. And very cold is better than hovering around +-zero. Snow brushes off, it is frost and melted snow that are the problems. I carry some adhoc deicing spray with me which helps if it is just a case of clearing off some frost when OAT is above zero.
I carry some adhoc deicing spray with me
Is it OK to use automotive deicing spray? Or do we need TKS fluid in a suitable spray bottle?
Is it OK to use automotive deicing spray? Or do we need TKS fluid in a suitable spray bottle?
In my opinion to clear frost when there is no refreezing risk anything non-corrosive is fine. In the Faroe Islands we used (at the Air Trafffic Controller's suggestion) a plastic bag filled with hot water dragged over the wings.
Clearly deicing fluid is needed if there is a risk of refreezing as it is made to adhere and then blow off as the aircraft accelerates for takeoff.
There are reports that the SR20/22 do not like to carry anywhere near as much ice as older planes with thicker wings.
I can't speak from experience but this is something to be treated seriously.
As an example, in my worst icing encounter which was ~30mm of ice at 4000ft, -5C, the TB20 could just about fly straight and level at 4000ft, max power (and I have a TKS deiced prop) and was not really controllable below about 100kt. I had to do a slow descent to reach and maintain 120kt so it would fly OK while de-icing. With a surface temp of +3C the ice came off at ~1000ft but took some 20 mins especially the buildup on the elevator which is an even more critical surface than the wings. At the other end of the icing spectrum, 5mm ice (mixed rime and clear - the usual thing) is barely noticeable on the airspeed or anything else.
Now, let's say an SR20 will go out of control with 10mm of ice... especially as you don't have prop de-ice so will lose engine thrust at the same time. You could pick up 10mm in 1 minute in wet enough cloud.
I know you have the chute but given the leg pulling which Cirrus pilots get for pulling the chute in some shall we say "interesting" circumstances you may not want to make the chute your "Plan B for Icing" 
Possible dead battery etc... I would be more comfortable going places in winter if i could park in a hangar. Any experience of this?
Certainly, if you can get a hangar for the night if there is a risk in the plane being covered in ice in the morning. It will save you loads of time cleaning the stuff off.
You should not get a dead battery overnight unless the battery was already shagged, but if you do then a power truck or a battery recharge (which will take some hours, plus a load more hassle because in most installations they can't be charged in situ) are your only options.
Is it OK to use automotive deicing spray? Or do we need TKS fluid in a suitable spray bottle?
There is a certain amount of "street wisdom" on these fluids. I think the incentive to save money depends on how much you use... My prop TKS bottle takes 2 litres so I buy the real stuff, 20 litres from silmid.com for about €200! That 20 litres will last maybe 10 years so there is no point in saving money on it. Also I would not use some ex-Ebay no-name fluid in a full TKS system which cost €40k to install, but I know some people do, and it is no rocket science because the composition is simple and widely available.
However if I had the full TKS system, which is capable of using up 50 litres in an hour or two, i.e. €400+ at the "full-paperwork" price, and I was actually using the stuff up, I would definitely be making my own arrangements for the fluid 
For spraying onto a plane, I would try either the TKS fluid or mix up some fluid of known composition like the TKS fluid. Don't buy stuff from a car shop - could be any old crap. It's like the Rain-X which is for glass and which makes your €3000 plastic window go cloudy...
Is it OK to use automotive deicing spray? Or do we need TKS fluid in a suitable spray bottle?
I use TKS in a garden spray bottle. Spray it on, wait five minutes or so, and it makes brushing ice off much easier. I've seen people with car de-icer, and it works, though I wouldn't use it on a plane with a nice paint job in case it does something to the paint.
I don't want to hijack this thread, because the question was pertaining to without deicing equipment.
In my case I have a Saratoga II TC w/ PIIPS (which is TKS-based) though. Only the prop and the leading edges of wings and elevator are deiced. There is no spray bar for the windshield, but I do get some fluid on the windshield because of the propwash.
I still wonder, how effective this system really is. Because I basically plan as if I wouldn't have deicing equipment. Which is of course in my case also the only legal option as far as planning (because it is non-FIKI).
What what be your limits here?
Do you have a heated stall warner and ice-protected fuel tank vents?
I have two stall warning vanes (one for flaps 0-10° and one for 25-40°). One of them looks like it could be heated, but I am not sure and also find no reference in the AFM.
The fuel tank vents are definitely not heated, but I assume they don't ice over.
I'll take a picture of the stall warning vanes...
