Honestly its all dependent on whether the weather wants to be nice or not, most of the time in December lakes are mostly safe to skate on, to get a official report u can just search up the lake you want to go to and most of them will have an ive thickness or a warning wether u can skate or not, and you can fish here if you have a license and they are extremely easy to get here i think like 25-50 dollars, and with hiking thats all what your willing to do most hiking mountains are open year round, and make sure u have good insulated boots cuz screw these winters lmao but have fun when ur here definitely a beautiful place to see