I'll be odd man out and say that 70-80mph down the open freeway in good conditions hurts nothing but your wallet at the pumps.
You have the rig to do it (unless its a F350 gasser, then you'll struggle with 70mph and that big a trailer and more $ at the pumps).
Talking ideal conditions, flat open road, no big X winds.
I don't think it will be as big a leap as you think coming from a moho and a trailer.
Unless you have a particular reason for a TT toyhauler, IMO toy haulers are better served in a 5ver. They typically have a lot more empty tongue weight to counter balance the max "toy" weight.
Depending on the size garage, that could easily be a 1200lb SxS and another 500lbs of bikes, whereas you'll have 2-3? race bikes. Much lighter in the back = more tongue or pin weight.
Plus you get more "home" for the same overall length going down the road, better handling, no messing with wd/sway hitches.
