On the 2015 Cruiser RV R24BHDS there's an option/upgrade for 50amp service and a second A/C. Reasonably all campers of that model might be built with 10 gauge wiring.
FWIW, the original single battery our ViewFinder came with also fed the fans on the fin fridge, the tongue jack, the CO/propane detector and some lights when not on shore power.
The OP stated the fridge was not on LP and it was obviously not on shore power, so presumably it was on battery. They had just used the battery for the tongue jack and they said some lights were in use. CruiserRV puts at least two rams/arms per slide so presumably the motor isn't some wimpy little juice sipper.
The OP said this hasn't ever happened when on shore power. It really sounds to me like it was just too much draw on a battery that the OP hasn't checked the status of to begin with.