First, if you camp in the redwoods themselves you will be lots of shade so if you want to go several days on solar then try to find a sunny campsite,
Yes, you will need a charge controller. Are you are planning a portable solar system or a roof mount?
If you have the Gopower prewired system which I think is what FR put on the 2018's its a roof mount system and they provide a spot for the controller inside one of the cabinets. You can get a kit with a controller and a solar module, or buy them separately. You can but you don't need to buy the Gopower kit.
If you want to have a portable system you can connect the controller directly to the battery (via a fuse for safety). You can mount the controller on the solar module, in a storage space, or anywhere else that is convenient for you.