Interestingly in this clip the Austrian pilot in his DA42 only used a satellite phone, on a St.John’s – Horta sector. It is a great testament to the DA42, and TurtlePac. This sector is ‘only’ 1200NM, so arguably available to Comanches and Bonanzas fitted with tip tanks.
There are bits of oceanic airspace where ATC publish a number for sat phone contact. Unfortunately that didn’t apply in the airspace I flew through (I was out of VHF range in the Indonesian archipelago and oceanic airspace between Indo and Aus).