Where and when should I do my long run?

I have to run 17 consecutive miles one day this weekend. It will be hot, so I'll have to get up early. Now my options are to run either Saturday or Sunday, and either in Ithaca or along the Outlet Trail.

Which day should I run? Well, Saturday is my typical long run day. It lets me rest and gives me ample time to cross-train on Sunday. When I do my long runs on Saturdays, I return to running on Mondays. On the other hand, the race was on Sunday, and now I am off by a day. I typically rest on Fridays, but tomorrow, I'll be cross-training 40-60 minutes in place of a 4-mile run (I want to take it easy tomorrow). If I run on Sunday, I will probably have more sleep, since I typically go to bed later on Fridays than on Saturdays. But running Sunday means I will have to run Monday as well (I have trouble maintaining a schedule otherwise).

Where should I run? The Outlet Trail will be more interesting, more sheltered from the sun, less hilly, and better on my legs. It is 16 miles out-and-back, so I would only need to run one extra mile. It's also a 45-minute drive from Ithaca. Running in Ithaca is more convenient and lets me sleep later. On the other hand, I'd be more exposed to the sun and would have to contend with more hills.

Please help me decide. I get tired of making these decisions for myself. =)