I'm from Canton, CT, but do most of my sailing in Hebron, CT. I've done some research on Lake Champlain.
one night at woods island state park (or knights island just northeast)
2nd night at valcour island http://www.byways.org/browse/byways/2479/places/32487/
for a better one, use google and search valcour primitive area, it's the first site that comes up.
The campsites are less than twenty miles apart. You have to go around South Hero Island, but that's the milage going around.
Launch from Mallet's Bay, but I think just south of Burlington would be better.
Day 1 30 miles
Day 2 18 miles
Day 3 18 miles
I was thinking though, the camping gear weight might screw up the wieght distrubution, so I was thinking of starting closer. That way I could drop off gear and just do some sailing without it. On a small lake, I was easily able to do 20 miles (according to my GPS) in 6 hours. That's with a lot of direction changing.
But, I've noticed a large jetty which may make the travel much longer.
The problem with finding info on the lake is the lake is 1/2 in NY and 1/2 in VT so the state's websites on the lake are not that good.
And here's a website that sells books and charts on the lake. http://www.lakechamplainpub.com/
BTW, the Rhode Island hobie club http://www.fleet448.org/
does a sail out to Block Island (9 miles out) at the end of the summer. I've never done it, but I plan to do it this year.