In my game the two-seaters are bugged meaning Sims won't use them (as if an obstacle is blocking the path to it), but the campfires are not from what I can tell - Sims can still use them for all the usual purposes. Sims won't sit on the ground around them anymore, but I'm not sure if that's a bug. I wouldn't want to sit on the ground if it's freezing outside.
Other than this, I feel everything is in working order with Outdoor Retreat items and Granite Falls. I can place anything from the pack everywhere and it functions properly.