Just thought my experience may be helpful. Been on warfarin for 6 years for DVT/PEs. I have been overseas about 6 times since then. Australia is my base. I bought a Roche Coagucheck INR machine (not cheap) and monitor my own INR whilst overseas. If I have a problem I text my very lovely haematologist but overwise have pretty much done my own dosing whilst overseas.
I do wear stockings only on flights more than about 3 hours and wander round every hour or two or my legs get really restless. I figure therapuetic warfarin puts me at less risk than most people on a plane to get clots.
The other thing I have sometimes done is rather than adjust for time zones, just keep taking the warfarn each 24 hours, so when in Europe for a week or two I just take it in the morning rather than the evening in Australia, that way I don't have to worry about 12 hours time difference. Then when I come back it goes back to the normal time. Can be harder to rememebr to take then though.
Lastly, I have got travel insurance every time I've travelled. In Australia I've used Covermore. But recently trying to find medical only insurance I have had a lot more trouble. Select only companies tend to be more exclusive.
When I started on warfarin some tool of a doctor told me I should never travel to a non-first world english speaking country again. Fortunately since then I've had specialists and a GP a lot more willing to work to make my travel possibilities eventuate.
Good luck, and it is possible.