How about a Hungary which used the chaos after the Napoleonic Wars to declare their independence?
Would that be allowed?
Basically a revolution breaks out and under the rule of a new king Hungary breaks free of the Habsburgs.
Following that all other nations quit the Empire and suddenly the former Holy Roman Emperor is stripped from most of his power after the Napoleonic Wars, only keeping Austria.

Would this be okay?
I'm busy right now so I can't make an NS yet.