Another year round WA flyer...but I don't fly in the rain anymore
If you have to store a fuel heli up north, the best thing to do is take the motor apart and clean it dry, then store the heli at room temp.
Don't hang it on a hook and leave it there if you live north of the Mason Dixie.....its use it or lose it up here for motor bearings, the nitro is like a magnet for water.
an alternative is to hover the heli 2-3 times a month if you do not want to strip the motor.
Lipos...theyre real easy to store: I run my batteries to about 60-70% discharge each flight (i.e. I fly 3000-3300ma from a 5000ma battery)...at the end of the flight, if I will not be able to fly for awhile, I just leave them like that and keep them at room temps.