This is complete junior varsity BS. Borderline bush league.
Do this or don't. Your compete level is pathetic.
You seriously need to decide if this is important or not. I believe it is, but I can't decide that for you. If you don't have the MAN inside you to get off your f***ing beach chair at the lake and run around that sum'bitch 3 times while stopping at the camp for a 6 pack every three house until you get to 80 miles, you might as well give up. Pull a goddamned all nighter if you have to. After you do that, you should be just about done with the beer by then. Sure, you'll be drunk and sick as shit, but that will leave you with 12 hours to get in a 20 mile run. Sleep off the beer for 8 hours and get off your ass for a 20 miler. You make me sick. I'm actually a little embarrassed for you.
Get off your lazy ass and make your dreams a reality, bitch.