This backpack has been stowed away at the back of my closet for a few months waiting to be fixed. It was being held together pretty tenuously: Sewed some of the smaller rips, then added repair tape to the largest one:

Next step will be to turn it inside out and add some more material to the large rip. The entire bottom is pretty much thin enough to let light through at this point. I'll try to post an update once I fix that!