Good point, if the fork happens just before the deadline then how about we wait up to 4 months for the minority chain to mine 2100 new blocks.  If the minority chain doesn't mine 2100 blocks by then, we'll call it dead and I win the bet.  

Regarding your term that if a fork happens, but BU reorgs so that the most-work chain no longer contains a block > 1 MB, I might be OK with that, but it's a bit unfair to me because what if we just get a random 1.1 MB block like we saw with bitcoin.com?  I could see that happening again, and I don't think that should count as a fork.  How about we define a "fork attempt" as occurring once the large block chain has at least 72 blocks built on top of it?

I am happy with Dooglus as escrow.