I've found that as long as there is no food for them, I've never had a problem. Through 8 years of owning a popup and TT, as long as we cleaned the camper out of any food mice could get to and gave it a good cleaning, I've yet to find a mouse or signs of them. When I say "mice could get to" I mean we don't remove unopened glass jars or canned food. Everything else goes inside. I have put decon in cabinets near holes for water lines and electrical cables in the floor yearly (Kitchen, Bathroom, electrical area, etc.) but never had any of them disturbed.
2020 Chevrolet 2500 LTZ, 2019 Forest River Wolfpack 23Pack15, 2014 EZGO Golf Cart.