Hi Ben- this is what we do when we have a large pot- we cut pipe insulation to go around the edge of a bucket, which can be bought at your local friendly hardware store. The size of bucket can be bigger for a bigger pot- this one is a 3 gal., you can use a 5 gal if you need to.
It something takes two of us to maneuver the pot in place- or take it out when it is a very large pot.
Place the bucket on the wheel and hold it in place using your giffin grip.
Then place the pot inside the bucket- being held in by the insulation.
You can then trim up the sides and bottom of the pot.
This - of course is not a green pot, but all I could grab as an example.