In the OP, the object was to do more "off-season" camping. So adding more solar won't do any good in the dark half of the year.
You need more AH for the "off season". IMO your calculations of needing fewer AH next year will only help in the sunny, warmer half of the year.
You can add more batteries or charge what you have more often, twice a day even - most likely need to do both. Alternative is to wait for the "season" to use the TC. Just how it is. You are not the first to wake up to a dead battery at night when first trying to RV in the "off-season". So it is "go big or go home" basically. :)
