technically no distance is too far to flat tow. It is the same as towing it around the block. As long as all the safety precautions are taken, IE safety chains, tail lights on the towed vehicle and a braking system on the towed vehicle. Coupe articles here on how to use the braking system of the towed deuce to your advantage. Plan your routes well and don't do stupid stuff with it in tow and I would think you could tow it anywhere you wanted. Leave the trailer at home. Actually it wouldn't be as severe as a fullsize deuce because of the reduced weight of the bobber. Keep in mind that adding weight to the m109 will decrease any advantage you get for reducing the weight of the towed vehicle. Now then, how many people are you looking to haul? Last I heard a deuce will only haul three, and not very comfortably I might add. More like two in seudo comfort.
I am considering doing the same kinda thing, but using my M35a2c with a s250 shelter in the bed flat towing my bobber or modified 1031. Whichever the even calls for. Use the deuce with the shelter as my base of operations and the towed vehicle for play. Also should you have a problem with the primary deuce, the towed vehicle can be used as a life raft or tow vehicle should the need arise.