I love the fact that we can have NPCs from every world inside our own home! It's so much more immersive and it's honestly one of my favorite activities to try and make my home look like an actual area in the game. I think there could be so much more with the House Guests, there's so much potential yet to be unlocked! Here's some House Guests I'd like to see
Your Professor + Ambrose (Maybe these can be received via a quest)
Wizards (This can be Wizards we've talked to in quests, or just randomly generated students of varying schools)