Bobby J, what's with the Lions? There is no definitive answer to your question. Temps. in the 20's, perhaps you can deal with. You need energy when in the cold, so I would avoid boondocking - you need electric.
I camped in a winterized campground I the 20's, that had the water lines heated. I rigged up a water hose with heat tape spiraled around and then encased in a insulation tube.
There are several recent good threads regarding dealing with the cold. Most have given suggestion for the water bay. I feel the weakest link is the lines to the rear, such as for the rear bath (if you have one), the water heater and the clothes washer. I am not sure how they can be heated. Periodically, flowing water in the lines, helps to prevent freezing.
Gale & Hank- 2012 Berkshire 390BH