actuators
I have not had the problem with mine here in Texas, yet, but it does not get as cold down here. I do know that most actuators respond slowly in colder temperatures, especially if lubricated by hydraulic fluid, but mostly due to the close tolerance required for them to work properly, and in extreme cold weather, the high quality steel may sometimes draw just enough to not maintain a close snug fit. Do like one of the reponders said, push it up and down a few times, this will cause enough friction heat to make them work. Replacing them will just give you a new set to push up and down, unless you have high miles, and the shaft may be worn enough anyway due to usage causing it to not stay up.