garmp1 thanks for the additional info. The reason behind asking the "trip" question was to get an idea of how much stuff you would need to carry. For shorter trips you don't usually need to carry as much compared to transcontinental journeys. For 2 to 3 week trips, you likely won't need to carry much, so you are less likely to need a rig with a higher OCCC.
Even if you only plan to use the commode, you may still need to winterize. After all, there are water lines to the toilet when you flush. You can avoid the winterizing process by not putting any water into the water tank and not hooking up to water. Use bottled water in the toilet when you flush. Still need to dump the tanks. I also use a small amount of RV antifreeze in the toilet as a "water" seal to keep out any residual odors from the black tank. Best wishes.