Great start.
Cutting the gear weight may help with increasing the mileage. 55# is a lot, you should be able to easily cut that to at least 30# without spending a fortune on UL stuff. When it comes right down to it you really need very little stuff.
Food and water should be resupplied along the way. Carry enough to be safe, but restock often rather than carry much for very far. If you know for sure there will be a store buy food daily. If you know there will be water, restock as often as you can, water is heavy. Have a little in reserve, enough to be safe, but don't weigh yourself down unnecessarily.
Yes there may be times when you may need to carry a lot of water, but don't do it when you don't need to.