If the gun is clean when loaded, and there is a good seal on both the breech and barrel side, then you shouldn't have a problem. Keep a used primer and put that into the breechplug to keep moisture out when not hunting. If the sabot fits tight, and with most T/C barrels this isn't a problem, then unless the gun is soaked in water, it should keep the powder dry.

If you've fired the gun, however, you MUST unload and clean it every day. T7 isn't as nasty as BP or Pyrodex, but it is still hygroscopic (attracts atmospheric moisture) and will accelerate corrosion. If you've fired the gun at some point during the day and reloaded, shoot the gun clear in the evening and then completely clean it. If not, then it should be fine. Also, if it is cold outside, do NOT bring the gun into your house or other heated space with a charge in the bore. Just like a cold can of beer forms condensation (sweats) in the summer, the gun will too. Not good.

I don't know what Kansas law is regard what's considering a loaded weapon for transportation regarding muzzleloaders. In Iowa, as long as the gun isn't primed, it's considered unloaded. If Kansas considers a charge in the barrel "loaded," then you might have to shoot the gun every evening before you drive home. Check your local regs or ask a DNR officer about this.

Mike