I've done excruciatingly long GV missions on several occasions. I've gone to strats, to remote bases, etc.
Once back in AHI on the original Pizza map I finished a mission and just as I was getting back to base it was captured. I continued on to the next base and the same thing happened. And it happened two or three more times. After four hours of driving our entire section of the Pizza was captured and I had to ditch.
Also, on the big map with all the islands I took off on a PT mission one day. I covered at least half the map over about a six hour sortie, rocketing strats (when they were spread out) and getting 3-4 aircraft kills along the way before finally rendezvousing with a CV to land successfully.
I like those types of missions but I rarely have that much time available anymore.