Keep the bags out of the rain and next year you are good to go. As Darren Garrison said, “it will become even more mulchy.”
I do this every fall with closeout stuff. In my case I take it out of the bags or bales or whatever and pile it up in a spot out of the rain. Before the first frost I have an infinite amount for plant insulation. Winner!
It seems like I am missing something. This is the mulch you buy that you just leave outside for years after removing it from the bag? Does everyone re-mulch every year? Is that something I should be doing?
People re-mulch every year in New England. That is how you can tell it is finally Spring. It gets scattered around and deteriorates during the Winter. I am surprised mulch season is truly over anywhere. I need several more bags to cover some light spots that I missed about a month ago.