I am having the same issue right now while trying to buy my first truck camper. I have a wife and we are about to have our first child and will be traveling for several months at a time during the summer and a month or two during the winter. The outdoor shower will be fine during the summer but I worry about wanting an indoor shower in the winter. For those who do a lot of winter camping what is your solution for showering in the winter? We will be camping at or near ski resorts a lot of the time
We use ours every weekend, previously in AK, now MT on ski trips, year around, winter is no obstacle. On demand propane water heater, grey water at ski area parking lots goes in a home depot bucket during the day, then in the snowbank at night. We don't have grey/black tanks. We have lived in our camper for extended periods up to three months, and also do frequent 2+ week long trips. A shower with a family is nice. My wife/kid use it every few days, I use it more because I can.
Our camper is only 8', plenty of space in our design for a big ass shower.