Sam would be so tall he actually gets to see slightly above how tall he’d be as a regular guy! If Dean’s shifting around at all, he might end up clinging to that spike of hair Dean’s so proud of, and complaining.

And Dean would let him, because Sam’s earned this and deserves to be tall, dammit.

Fun fact – tiny Sam standing on regular Dean’s head would be just as tall as Jacob when he’s full grown.

The brothers – To keep it interesting, I’d say Sam ends up swapping into Jacob, and Dean into Sam! That makes Jacob the shortest of the group, and poor Sam, who has the least experience being full-sized, finds himself too tall! He might not even get as far as discovering how strong he is now considering how nervous he’d be around the two really tiny guys. While Dean’s just complaining about how long Sam’s hair is and it gets in his eyes and how can you deal with this Sam.

Jacob – Jacob would be super weirded out to see how big everything is. He’d also have to concede that, yes, he very much does seem to stomp around and cause earthquakes. He’d have to hope the Sam-swapped-Dean was able to get over the shock enough to look after him, because he doesn’t have the skills like the brothers do for surviving that smol!

It depends on the motel. Most likely for a few hours each night if he has the time during a hunt. If he ever lucks out and finds people, he wouldn’t be back that night unless they rejected him – a painful possibility for a little guy who travels with a human! Dean gets a bad rep just because of what he is. If instead Sam finds rodents or insect infestations, he will get out of there and stay in the room. (Mice don’t count, Sam loves mice.)