Due to circumstances beyond my control, I have had to unsubscribe. My question is what will happen to the house I bought in Mooshu? Will I still have access to it or will it disappear from my account?
Your Wizards are safely stored at Ravenwood School of Magical Arts. Even if you uninstall Wizard101 from your computer, your Wizards, all the belongings, house and experience earned is still safe.
This includes your house, as it is a MooShu style house, but it is not actually located in MooShu.
If you are logged off in a subscription area, and your subscription expires, you will be returned to Ravenwood Commons and you can continue to play in the Free to Play areas of Wizard101, including your house.