Not so much UV up in Alaska, and not as much heat. Still, I've heard that dacron with latex is indeed durable.I have seen Ceconite (heavy Dacron) and aircraft dope last 25 years with minor maintenance touch up in Alaska.
Latex is unknown. Depends on the quality, I think some brands have a warranty of twenty years on homes.
It depends on how much flexing.
I painted a windsock with yellow latex to test the paint adhesion. Of course it cracked and flaked off in less than a year. But that was extreme flexing in constant wind.