Don't know if this will work. It's the route as I inputed it into RideWithGPS.
https://ridewithgps.com/routes/48591975?privacy_code=LWeIbyuXz1KibO41oVVo691Knmo1wQCS
I can only comment on part of the VT side...
1. Your route skips the trail south of Hero Island. Very neat ride that uses a boat shuttle to bridge the gap left by the removal of the old railroad swing bridge. Just make sure you check the shuttle schedule to make sure it operates on the day you plan to use it. Also check to make sure the trail is open. When I came down that way in 2018, a freak spring storm had damaged the trail and the section that crosses the lake closed.
2. Burlington is a fun town, but indoor accommodations would likely be pricey. One alternative would be to stay at North Beach Campground. It's right long the trail, a bit north of the center of town. Like many/most state parks in VT, this municipal campground has lean-tos. They are actually very large. Book in advance as the place can be busy during certain times of the year.
3. Leaving Birlington, I followed the Island Line Trail to Queen City Park Rd. and then picked up U.S. 7. The early part of 7 has no shoulder, so I rode on the sidewalk. (There were no pedestrians.) By the time you get to Holmes Drive, a shoulder appears. You'll have to ask yourself whether veering of onto Falls Rd. and Marsett Rd. just to skip some of U.S. 7 is worth it.
4. Once you get onto Bostwick, things improve greatly. Again, you will have to ask yourself whether it's worth veeringoff to the lake for a short section rather than just staying straight through Charlotte. The Old Brick Store at the intersection of Greenbush and Ferry Rd. is neat.
5. Careful in the center of Vergennes. Traffic can be heavy. Both times I grabbed a sandwich of the c-store at the intersection of SR 22A and MacDonough and took it over to the park by the dam.
6. From Vergennes, I stayed to the east of 22A for a while and then got onto the 22A all the way to Orwell, so I can't really assess your route. I can say that VT dirt roads are usually pretty good, but I would check them with Google Maps Street View to the extent you can just to make sure. (For some reason, RWGPS no longer lets you view a route using Google Maps.) I planned to take one unpaved road that was impassible on anything but a full on MTB. And keep in mind that dirt roads will likely slow you down, especially if they are wet.
7. The store on SR 73 in Orwell was nicely stocked both times I stopped there. From there, I headed SSE to Castleton.
Hope this helps.