I'm going to bump this up because I'm interested in doing the opposite way, from NS to Ont.
I used to do the US routes by car back in the 90's and I'd guess the question would be, "do you intend to use the Toll expressways in the US?". The mileage isnt much different and as I recall but the roads were a hell of a lot better. We used to do TCH to Salisbury NB, then Hwy #1 to St John NB to St. Stephen NB. cross the border follow hwy #9 to Bangor Ma. From Bangor it was express ways I-95 to I-495 (bypass) to I-90 Mass turnpike.and I-90 to Buffalo. In 95 DW was diagnosed with MS so the trips ended.
Figuring in the cost of gas and the cost of tolls there was little difference in the costs traveling either way (might be a bit different now).
However traveling from Ottawa, I'd select a crossing at Thousand Islands to I-81 down to Syracuse and then 481 to I-90 that will keep you on the expressways if that is your choice.
Since we got the RV in 2005, our past trips have been through Qc. The roads were pretty good with the exception of hwy 185, Riviere du Loup to Edmonston NB. I will never do that one again at night time. I'll swear that hwy has been under construction since 1976 when I moved here from Ont. Where it is good, it's really terrific and where it's under construction, well it couldn't get any worse if they really tried to make it worse.
Now there's one other option, By pass Montreal. There's a river crossing west of Montreal at exit 14 of the MCH 20, to hwy 201. Follow 201 to hwy 30 and then to hwy 132 and then back on to hwy 30 and follow 30 to hwy TCH 20. It would be best to Google this map area and chose the most suitable route to take as Never driven it myself. I have driven hwy 30 from TCH 20 to Brossard in 2009 and it was great road then. The plans I understand are to include hwy 30 for the Montreal bypass.
Not much help but it's the best I can do because if we decide to go next year we'll be facing the same problem.
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