Route 3 in New York

We went across 3 pulling our trailer and didn't have any problems.

Except... Our GPS tried to send us on a dirt road for a shortcut to cut out one of the curves in Rt. 3. Just don't turn off the pavement. ;)

I only an hour or so from there, and have driven Rt3 many times. While it would be somewhat slower going than US11, it's not a bad drive, even for a big rig such as yours. I would describe that stretch of Rt3 as "hilly" more than mountainous, and curvy, but not twisty -- if you know what I mean.

US11 is OK too, just not as scenic IMHO. Rt 11B is just as direct, but on higher ground with some great long views north to the St. Lawrence River valley. Or, as the other poster said above, you could go all the way north and take Rt 37 right along the river. No matter which way you go, you'll wind up at Rouses Point to cross into Vermont.

We take RT3 all the time but we only go to Tupper Lake, Saranac, or Placid. If you do take RT3, Harrisville speed limits are strictly enforced.

X2 go up to US11 and cross that way. Route 3 is a State Route and runs right thru the mountains. Route 11 for the most part is flat and easy drive.

Only reason I want to do 3 instead of 11 is I want to spend a couple days in the Adirondacks before heading over to Vermont. I'll take 3 to 87 to 11 into Vermont.

3 is doable, but 11 is a better choice in my opinion. I've driven both in our motorhome...

I'll just add that if you have a little extra time, the run further north along the Seaway is a nice scenic ride.