I have a solo stove bonfire that we take with us. I have a 2018 M2 TS. I am able to put it and a 22 inch Blackstone in the back passenger storage compartment under my water tank. I don't think anything bigger than a bonfire would work as the next step up is a much large diameter. It really depends on your model number as to the size of the storage bays.
We really enjoy the solo stove as it can burn pretty smokeless with a variety of wood. on cold damp days when everyone else's fires are smoking like crazy the solo stove barely puts any smoke out. it is pretty efficient at burning a lot of wood quickly which is another reason to keep to something like the bonfire or smaller.
Paul and Debbie