TP always goes in first for me, it always was in all my cars 24/7. I have travel most of the road West of the Mississippi. That the first thing I check for in bathroom. You don't have to go out in the wilderness for a oh no moment. LOL
Every October, I'd hit the road for 3-4 weeks, just traveled around the country. Finally got rid of the small cars and got a 1952 GMC panel truck (long bed). A bit of work customizing, insulating, electric heat, power ventilation, fridge, bar, hot & cold running water, 4 channel amp & reel-to-reel tape, it didn't matter how cold it got outside, I'd park where ever and "camp"... still had no place to take-a-dump. When I had a couple of rolls of TP, I'd change the Truck's filters (TP oil filters).
Wifey and I honeymooned in that thing, wintered in Ontario. The whole back turned into one huge bed.