Party night and a 10 miler ahead

Well this will be interesting - we are off to a party this afternoon which will probably go on until the wee small hours and I have a 10 miler the next day. Alcohol is obviously off the menu but how on earth can I get an early night in without being a party-pooper?

I only have a limited window for the 10 miler as we have a sunday dinner at the other-half's parents house too.

Sounds like it will be interesting.