Terry: it's not a 100% guarantee, but it should be sufficient for your purposes (the more obscure failure modes mostly relate to C level globals, Python level module globals, pickling, and module import having side effects on state in other modules, and it's unlikely you'll hit any of those here as long as the main "tk" module and any modules it implicitly imports stay loaded. If you do end up getting bug reports about this, we can treat those as a bug in the affected modules)

As far as the module count goes, a plain "import tkinter" gets the imported module count up to 63, so that's presumably an absolute lower bound on your efforts.