for a second I was like "aha! I get everything except the last province with feast and hermit (gold pile was already empty), then get the last province with horn of plenty!! but then I realized that if I'm only playing cards that trash them self, I won't have 8 different cards in play.
and then just now: oh wait, how am I going to trash the cards I gain. I still need watchtower!
I can trash the watchtower by buying a farmland, but then I can't trash the farmland!