We are expecting number 2 here shortly and we have both never been away from our son at the same time before over night. Any helpful tips?

I am having him sleep in his pack and play during naptime in a different room to get him adapted to a change.

I plan on packing some of his favorite toys, comfort things he sleeps with, and his favorite clothes (anything with trucks and dinosaurs lol.)

He is staying with family but he doesn't spend much time with. He does absolutely love them when he sees them though. They are unable to watch him prior. I was thinking of writing down a few things like his routine for them, is that overkill? I don't want to be overbearing.

Thanks!