Bill in Houston from Houston on 6/5/2023 4:32:55 PM:
Found this - "Surface. Mostly flat and off-road, the Erie Canalway Trail includes various surfaces. About 45 percent of the trail is paved, while 41 percent of the trail is stone dust, and 14 percent of the trail is on road. Very few natural stretches of trail remain."
My wife and I ride a MTB and town bike on our long trips. We find them comfortable and reliable.
We saw lots of people on road bikes. You and your friend should probably ride the same type of bike so that you can hold similar speeds and share inner tubes.
We did encounter some softer spots that would have been a little sketchier on a road bike, but they would be doable.