The front tires, edge to edge measure just barely over 6 feet. So it will FIT on the dolly.
That would not fit on the dolly I have borrowed in the past, but I'm sure they come in bigger sizes.
With a tow bar you risk the tire flop problem, with a dolly you have difficulty backing up.
My own preference would be a trailer, though you need a trailer big enough to do the job. I have an 18 foot flatbed and have hauled several trucks on it.
A shorter truck with no motor works fine, but the last one I put on it was complete with motor and bed, and was long enough that the wheels were all the way forward at the front and just barely on the trailer at the rear.
I won't do that again, it was a slow and at moments scary 45 miles. The problem was that I could not adjust weight on the tongue and had too much weight up front. At 35 or 40 it was fine, but any faster and it was not stable, so I slowed down and did fine. And yes my trailer has brakes and they are very important with a load like this.