I'm using the winter months to consider my options.
Matt, let me give you some (unsolicited!) input of your prospective North American tour. We'll leave aside the vexed question of the pandemic for the mo', 'cos what I have to say will surely be in effect when do do venture into these parts.
Just returned from my mini-tour of the extended neighbourhood, S and then W from Ottawa along the Rideau Canal, camping at lock-stations. (We'll leave the story of Annie Laurie until the full account - rest assured, it wouldn't have happened without her intervention.)
I spent the first afternoon and the entire second day battling head-on winds of 35-40 km/h, gusting to 50-plus. On level ground, I was having trouble staying in 8th; any rise at all, never mind hills, and I was down to 6th, and often lower still. (With a 36T front ring, remember.)
There were times when I was saying to myself, "Why is this happening?--I'm not in Saskatchewan..."
Occasionally, I found myself thinking of our conversation about your angling through Ontario en route to the Pacific coast. My summary suggestion is this: if you're going to tour N America horizontally, I'd recommend starting on the
west coast, and cycle east with the prevailing winds behind you. There are more enjoyable ways than by air to cross N America with a bike -- I'd suggest the train. Things is, if you ride to, say, Vancouver, you're still got to take the plane or the train to get back east; so if you want to make the prevailing winds your friend, I'd suggest you let the train buck the wind for you, and then cycle back east.
My return journey on my wee trek simply confirmed my existing bias: with that 40 km/h-plus tailwind (it eased off a little as I turned N and W), I sailed along in 9 through 12.
Cheers, John