Welcome. A local over nighter done two weeks before departure testing all the systems before all the stuff is loaded makes a lot of sense. Then there is still time to get a repair accomplished without messing up your schedule.
If you have a tire with a slow leak, try a different valve cap and see if that stops the leak. Had a defective valve cap incident happen on a motorcycle trip once. It began pushing on the shredder valve and letting the air out very slowly.
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic w/ twin beds, 50 amp service, 1000 watt solar system, Centramatics, Tuson TPMS, 12" disc brakes, 16" tires & wheels