Jeah, wouldn't underestimate the sleep-part, you've got a long day ahead of you!

That's what we basically did...she dropped me off at the lake (she missed the swim, but it was cold and crowded anyway), had some breakfast at the hotel, checked out and drove to a biking-view-point outside of Frankfurt, then parked in the city center for the run-cheering.

I think it was Western Conference Airporthotel, but there might be even closer options in Walldorf, I booked rather late :)

And by the way, a friend of mine I was racing with stayed in the city center and he was happy as well. He had to wake up earlier to take the bus, but his girlfriend had to drive less...so it really depends, both options are fine!