Yes, you can get away with using SQL EXPR if you keep your nodes & performance polling low, but sooner or later it becomes a pain, and you need to migrate away from it.
In your case, you might be able to hack around with it, and move the DB. It's a bit of a hassle though.
If you were to move IMC to a new server, you would need a new license key anyway.
Talk to your local HP SE. They might be able to help out with getting you a new key issued for when you move to a new server.