Hi there! I totally understand how you feel. We go over to DH's parents' house twice a week and DS always takes one nap there on those days. He acts exactly like your LO does. He will kick and scratch on the crib bedding and hoot and holler for what seems like forever. I just consider it part of the nature of unfamiliar territory. I think that your LO will settle down much faster once he's taken a few naps/spent a few days at the other homes. If need be, trying putting him down in the crib ~5-10 minutes earlier than you would at home, just so he'll have a better chance of falling asleep.
If it's been, oh, 20 minutes and he's still not gone to sleep, you might try doing the wind down routine again. Or, at least pick him up, say the key phrase, and put him back down. I also ask my MIL to darken the room where his crib is, and that helped a lot, too.
HTH a bit!