Do an energy use survey...actual or what you’d like to use. Your choice. That determines the battery amp hours needed, which determines the solar watts you need to recharge and the controller size. If you guess, you will be either undercharged or overpaying.
“battery charged for a few days of boondocking” is absolutely wrong. A properly sized solar system recharges fully almost every day. Limping along...for a few days? Solar isn’t a new toy or experimental.