You do realize that unless you're hooked to shore power or running the generator, the outlets in the toyhauler have no power? The batteries on the tongue only run the 12-volt items in the camper, and not the 120-volt outlets/items. Two separate circuits.
I'm surprised you have issues after only a month. I never even unhook the batteris, and go for more than a month at times on some of the bikes/ATVs. I try to start them at least once a month, but sometimes it goes longer.
Finally, the solar charger on the tongue bateries will keep them charged up. But, I just unhook (actually I installed a three-way switch) those. The camper, even with everything off, will still draw some 12-volt power, and drain those in a month.
2008 Ford F350 CC 4X4
2012 Jacyo Octane T29A
2006 Yamaha Blaster
2007 Honda Recon
2006 TTR50
2012 YZ250F
2013 WR250R
2013 XT250