If you have room in the car - an old cooler with a frozen jug of water thrown in. I keep my reels in it too, to prevent the line from being destroyed. Just throw the boots in when you're done- keeps the car clean, too. The frozen jug of water isn't very expensive....lol You even get the luxury of a cold beverage. Google felt replacement soles, there's a bunch out there that come in kits with oversized soles,barge cement and sandpaper.
Charlie