Training & Nutrition - How to prepare for a long ride 1.5 weeks in advance?

I am going to my mother in laws in Tennessee next Saturday night, and on Sunday morning I am riding out to my wife's uncle's house...which is about 20 miles away. Then after we spend the early afternoon there I'll be riding back, a different route and it will be close to 50 miles total for the day. Which will be the most I have ever ridden. The longest I have ridden up to this point was 40 miles and I bonked, because I didn't eat anything that day...I know stupid. Then the last long ride I took was 28 miles and my muscles were killing me at the end of it...but I was riding my 45lb 73 Schwinn Continental...

So I am determined, saying the weather permits, to take this ride when I go. The route is absolutely stunning and I really really want to go. So I want to know what tips you guys have for preparing for this ride. It is not too hilly, but it has some steep hills, the longest climb is 600 feet at a 5% grade. I plan on taking a banana or two plus some granola with raisins and/or a peanut butter sandwich. I have read somewhere to stop every 15 miles or so and eat...

With such a short time in between now and then should I increase my mileage at home or stick to my norm and save the muscles the grief?

if you mean this saturday the 10th... no, there's no training you can do.
if you mean next saturday the 17th, yeah, you can do a couple of things. First off, get out this weekend for 30 miles on Saturday. Ride again on Sunday, but just roll around for a while if you're wiped out from the 30 miler. During the week, try to get another ride or two in of at least an hour - go a bit faster, do some higher speed efforts.

You can do this ride no problem, it's simply a matter of pacing yourself. Take 2 water bottles, have a banana or 2 in your jersey pocket, have a good meal about an hour or two before you start - like a big bowl of oatmeal for example. Drink a water bottle at about one per hour, taking frequent drinks. Start eating after your first hour on the bike; a bite every few minutes as you pedal.

After 2 hours, stop, get off, maybe hit a c-store, drink an OJ or V8 (I don't like Gatorade but if you must...). buy another couple of banana's or maybe a fig newton or a powerbar. Refill your bottles.

Just roll easy the entire time. No need to set any records; even little efforts and small hills will start to add up on you.

You'll be fine.

Oh yeah, make sure the bike is mechanically sound and tuned, and that you don't have any fit / soreness issues.