Impressive. I've basically watched only half of Season 5 to this point. There have been other issues and shows in its place but what I've seen is, frankly, magnificent. I have always loved the show - it ranked either fifth of sixth of my best shows of the 2010s and I said if I'd seen the Fourth season before that (the strike delayed it) I would have ranked it higher. I never understood why Season 4 was given so little respect from critics. I thought it was at the same level as the first three - and considering the final scene basically told us that the four seasons were one overarching story only made me love it more. (I'm told there's no conncection between Season 5 and anything previous.)
Did you ever purchase Noah Hawley's companion to the first Three seasons THIS IS A TRUE STORY. There are scripts for the first episodes of every season and he gives an explanation behind much of the action, characters and themes behind all three seasons. I recomend it for someone who loves the hsow as much as I do. The final scene of the third season is printed out and the stage directions for the interaction between Gloria and Varga. I won't spoil it for you (in case you don't own the book) but he seems to have the same theme for the ending - Schrodinger's Cat - that you suggest.