Can you just bring them to the library or Goodwill?
Library is a pain with a zillion rules and only one day where they take them. My fabulous SIL just told me she would take them all and sort through for herself and take care of finding a place to donate the rest. Phew. Big item. So Many Books. I already am bring tons up north for my house and to give to my reader son and GF.
Another complicating factor is since DH totaled the truck in December we have been renting one. New ones are a year or so wait, and used ones are stupid pricey. He found one in Houston so we will probably buy that one next week and fly out and drive it home, depending on whether transporting it is feasible. The rental is about ~350 a week, so not an ideal situation at all, but required.