OK dad, I’ve been wihtout a lawnwower most of the summer. I want to take one last swipe at the acre with the push mower and then use the lawn sweep to clean it up. If I take the bag off the push mower what kind of trouble do you think I’ll find if I try to chop up the very long 1’+ bent over grass and the leaves on top of it?
Depending on where you are you may be alright but not too short so you don’t stress the grass.
If you still have some good light and it’s not cold you can do the following
If less than 4” cut it down to 3” and you’re done.
More than 4”? Cut no more than 1/3 of it.
Give it a week or so and as long as there’s still some good light and it’s not too cold repeat.
You can read more here
https://www.homesandgardens.com/gardens/should-i-cut-my-grass-short-before-winter