With all respect to the OP and the position they were in I am confused about why one would want the Tow Dolly "Towed" somewhere to repair a flat tire.
NO service company or tow truck driver is going to tow a vehicle with a flat.
Maybe I am missing something here but it would have been better to just call and tell them you had a flat and what size tire you needed and left it at that.
This is not to say that the outcome would have been a great deal differently but at least the waters would not have been muddied by the towing rquest of the trailer.
Sometimes you just need to keep focused on what you really need instead of the solution you want.
