Imagine a vampire getting frustrated with a realtor because this is the fourth time they've arrived at a house they're interested in to do a walkthrough but the owners aren't home and the realtor, as someone who doesn't have ties to the memories created in that home, can't invite him in.

This also has fascinating implications for house flippers. If you only live there while working on it, have you not amassed enough "home power" to keep vampires out? Does the power of your previous home follow you to a new address if it's mostly the same decor?

could you wear a tent like that and vampires would be unable to bite you?

I feel like they can't enter your house, as in get their entire body over the threshold. But there's no magical forcefield over the doorway, so if you were standing within arms reach they could grab you. The tent thing is kind of a moot point though, as there's nothing preventing them from attacking a domicile, so they could just tear it or even just poke you with a pointed stick.