I have to be completely honest here. I would not add any new snakes until your living situation changes. Without proper quarantine you're putting your other snake at risk. Simply not worth it. And if all goes well this time, next time you'll be putting BOTH at risk.
I have a friend who QTd two new animals in the same room and, unfortunately, one had mites... Long story short... Both animals sadly passed away.
Simply not worth the risk in my eyes. And not fair to the established animal(s).