You'll do great. Just be on the lookout for someone going the pace you want to go (and be sure you don't go out too hard - know ahead of time what pace you think you can maintain for that far, and don't fall into the trap of pushing harder early on because you feel good). I love riding alone, personally. Then again, riding with new friends is fun, too.

I think nutrition varies from person to person, depends on the weather, etc. I've been doing fine on my long rides with the following: 2-3 Gus, 1-1/2 packs of Shot Blocks (a couple of blocks every hour or so), 2 Power Bars, a bunch of Gummi Bears (gotta have something fun!) and Heed. That is what I've actually been using on rides 90 - 120 miles long - I've been carrying more than that. And most of my long rides have been in the 48 - 65 degree range. The extra Cytomax powder is a good idea. And an emergency $20, just in case. Just don't wait until you feel like you need it to take in fuel.

I definitely agree on the short breaks. I seem to feel better stopping only when I need to pee or refill my bottles, not eating too much at a time, and not stopping for long enough for my legs to need a warmup all over again. 5 minutes if I can do it, and I definitely try not to stop for any more than 10. Last Friday's long ride I probably didn't stop enough - it was raining for a lot of it, and I wanted to get as far as I could before my ride caught up with me. Pretty much slogged on. Then I flatted anyway, and found out my spare tube had a pretty short stem, my new CO2 cartridge thingy didn't work, and I didn't have my patch kit. I muddled through, but ended up with a 23 minute break at 70 miles. Felt awful for a while after that, until I slammed some Shot Blocks.

I hope you have perfect weather!