We are taking simple things, sandwiches, cereal, easy prep stuff for most meals. Probably take something to grille at least one night. Being Mexican, I don't eat MRE's

. This will be the first time I take a fridge. In the past we've taken ice chests, both parks have stores where you can get ice at a premium. I am also bringing an ice chest.
Great! Driving through San Marcos, we can meet you somewhere...
Roads are unmaintained and a little rough at times but we will not be going too fast on these. I also thought of doing my timing belt this week since truck just passed 200K but will wait until after the trip. I will let others with more experience chime in regarding your question but I would think you would be ok.