After years of dialing my pack weight and pack size down, I find myself in a position where I want to carry a heavier load again, both for food and the occasional extra insulation. My gear is relatively small in volume now, but packing it into my largest backpack, a ULA Circuit, only leaves enough space for about 4 days worth of food with my 3-season gear list packed in as well. Maybe I could fit another day and a half's worth of power bars in the cracks and corners between all the other gear, but what I want to be able to do is fit 7+ days worth of food, plus my 3-season gear set-up, without having to perform a Houdini level vanishing act with it all just to fit it back in my pack every morning.
Lots of backpack manufacturers advertize their backpacks' volume as the sum of all the pockets and compartments. ULA breaks this down pretty straight-forward. The ULA I'm using, for example, is a 4200 cubic inch (~70 liter) total volume pack, but the main storage area is only about 50 liters in all. I think I need at least another 10-20 liters of space in there, and I could do without almost all the pockets.
What is the market for packs that have a main storage area in the 60-70 liter range like?