Going on two weeks sans Camelback, testing a meduim Revelate Tangle frame bag. I can fit everything I used to carry with a little space left over. Not a whole lot of room for clothing layers, but the left-side zip has two little stash pockets (perfect for my phone). This is largest bag I could fit without losing water bottle cages - I'm not sure I want to move water storage inside a full frame bag.
That little hollow doesn't get much sun. It hit 56F yesterday, but the ground was still frozen and the air felt like a freezer. The higher trails drain well (bedrock ridges) but the lower creek trails hold surface slop for weeks - full on mud mode.