Generator first, and add a second battery, solar later. Gennys work the same in all weather conditions, solar does not.
Those worksheets for sizing a solar system are pretty much a waste of time and energy. Go big or go home unless you are strictly a fair weather camper.
Solar equipment is at its lowest cost per watt in history, and can be built in stages if need be.
In a TT you are quite limited in space for batteries so the larger the solar array the better. The object is to fill the reservoir faster than it is being consumed.
