Hmm, so much for a nice warm place to take a dump... thanks for the advice!
Oh I'd 100% use the chitter. Bring a couple three gallons of windshield washer fluid to flush with or dilute the black tank water.
Presume you don't have heated tanks/lines.
Look at the temperatures where your headed and decide whether you can find a way to keep tanks warm. (Not likely though unless your running heat 24/7 if it's below about 20deg).
Pack some water jugs. Unless it's well below zero if the jugs are at room temp in the camper at night, leaving them for the day with no heat won't freeze them up.