There's also a weird What if about Ivan IV marrying Elizabeth I? I'm actually researching a lot on which Russian PoD I should use for a planned rewrite of The Bear Migrates to the Pacific. Maybe I ought to give that a link as well. https://www.alternatehistory.com/discussion/showthread.php?t=216075
Ivan plus Elizabeth is either totally awesome, or darkly tragic even by Russian standards.
Will give that link a look.
So many interesting possibilities for a different Russia, so little time.