I learned this from my boating days - have one or two every so often along the escape route - you are not fighting the fire but fighting your way out. You want them ABC and manageable to use as you exit. So for us we have one in the bedroom, one at the kitchen / door and one upfront. We are in a 29' class A. I think the fire would be from the fridge if on propane during the night one should do it to get out. If there are more than two people, add more so each person has one next to where they are sleeping to fight their way out. Fires take over RV within minutes and the smoke will get you before the flames.
2013 Tiffin Allegro 32CA 24K
1996 Itasca Suncruiser 29RQ, 7.4, P32