Best place for a stay in Denver is
Cherry Creek. You are limited to 14 days and you need a vehicle pass for the MH in addition to the camping fee. They will give you a pass for the towed.
They have some loops with heated standpipes so you can fill your fresh tank. Last November we hit a VERY cold week in Denver - hit 14 below one night and stayed below freezing most of the week. Went through four 40 lb. LP tanks with a cold weather package on the rig.
Closest acceptable parks to Denver that we have found are in Golden or the
KOA in Strasburg which is open all year.
If temps drop below freezing where you are it is safer to winterize. Not a big job once you get the drill down. Lots of threads on the forums with detailed instructions.
Experienced or not I would not recommend trying the MH on snow covered roads.