^ yes that towing U describe is called "flat towing" or "4-down" ref'ing all 4 of towed vehicle's wheels on the ground rolling/braking. Only a minority of vehicles even qualify to have the nec preps for it, which incl a "base plate" mounting + wiring + steering bypass work, costing ~$4-6K alone...
My honda doesn't qualify, arguably a 'mistake' I made in choosing it before motorhome shopping/learning. U'll notice the 4-down vehicles many RVers tow are Jeeps, which all come standard with some special features anticipating being flat towed. But there are many other flat towable vehicle options as well.
and yes I think every tow dolly I've seen has been 100-102" (8.5') wide! That's same width as my rig & guessing class-As generally, but much wider than the biggest of pickup trucks!
I didn't even get into the "tow dolly steering" options in my
'braking systems' post above. Some dollies have wheels which 'steer' just a bit themselves; on others the belly plate where the car's (locked) front wheels rest, that belly plate swivels just a bit... 9 degrees in the case of at least one Demco model I looked at. Others have no such steering assistance on the dolly itself, & reco/require car's steering wheel be UNlocked allowing car's front wheels to turn a bit as car is being pulled around turns.
I'm still too nooby at this point to appreciate the significance of these features... like, if in a turn, my rig's rear inside/pivot wheel is able to clear a corner/obstacle, does that mean the 8.5' wide dolly's same wheel will clear it too?!
this RV-vlogging couple shares their experience leading to "divorcing their dolly" & getting a flat towable jeep as their dinghy, 15m:
https://www.youtube.com/watch?v=xb9VkVTfuT8