Eating during a 170 mile ride I am doing a solo, unsupported 2 day charity ride, covering 260 miles in total. I am not taking any panniers or backpack, the only things im taking will fit in my saddlebag and my jersey pockets.  

The ride isn't an even split with the first day a mammoth (to me) 170 miles, though relatively flat ~1,700m climbing. 

I have ridden 100 miles many times and have fueled myself sufficiently through pre ride eating and gels, snacks and drinks on the ride. 

I am also not worried about the post ride nutrition as have done this many times as well. 

The thing I am unsure on is this:

170 miles is just under 70 miles further than I have ever ridden in one go. 

I know I can go just over 100 miles in about 6 hours without any issues on gels and snacks. I have a brand that I know doesn't cause me any stomach upset eating ~ 3 gels an hour for this time period. 

I am estimating 170 miles will take me somewhere between 10 and 12 hours to complete. 

Would I be stupid to try to complete this on gels &amp; snacks alone? bearing in mind I'd have to carry somewhere close to 30 gels etc.

Should I try to find a place to stop and eat a proper meal? and if so what type of things should I try to eat? 

I would assume carbs, rice or pasta but not too much, would any protein be good too? Fat &amp; bread that sit on the stomach would be a big no no I assume. 

I was thinking about 90 miles into the first day so after about 6 hours, this puts me just over half way through the day and the area im looking at is on a big stretch between castles (im visiting 32 castles as the basis for the charity challenge)
I would look to stop at least twice and take on protein as well as carbs.  Try an omelette if you can get one on the road.  I would look to take some protein bars as well as energy gels, it will give variety as well as restore what you will blow through in 170 miles.  

You are also going to need to stretch, so suggest you plan on a 1-hour middle of ride stop...