Some of the west appalachia counties so far have gone 2-1 or 3-1 for Clinton.
If Clinton wins WV by 50% then she could succesfully spin that as, "I am the white candidate, you need me to win".
Then there is the popular vote issue.
She could still win it, if turnout was high enough, and she got 70+% of the vote in KY and WV.
Lets not forget PR has over 2 million registered Dems.
Large enough blowouts in PR, KY and WV could give her the barest lead in pop vote, even without FL or MI and that might prolong this primary fight for a month or two by slowing the rate at which Obama gets super delegates.
Though Obama is now only 155 total delegates away from 2025, so even blowouts in those 3 states would probably not give Hillary the nomination, but it could definetely give her reason to stay in longer.