However, what happens if one of you guys dies before the 2020 election?
It's more likely that Bitcoin goes up to $300k and eddie13 will retire to his private island forgetting about a measly 0.1 BTC bet

Seriously though, I was thinking about setting up a locktime transaction to a trusted third party who could pay out if I happen to die AND lose the bet. Or just set it up to go to eddie13 and hope he returns it to my heir if I win. In some ways this would be more robust than 2-of-3 multisig (fewer third parties).
But that's not particularly high on my priority list. Besides - the chance of me somehow screwing it up and/or forgetting to move the coins if I'm alive is probably higher than me kicking the bucket within a year.