I was just going through some old posts looking for a picture and I came across this topic by accident and saw I had said I would update on the durability of the blanket but I never did.
The picnic blanket has held up amazing! As you can see I posted this 3.5 years ago and its still like the day I made it. I live at the beach and it gets used all summer. I've washed it without issue, though because of the plastic tarp I hang dry it on our clothes line. Literally, best thing I've ever made in terms of function.