No problem with draft or size on the two boats your looking at, many 40+ footers do the trip regularly.
Another thing you need to consider is powering up the St.Lawrence once you
head west to Montreal from the Richelieu river. You should have a
boat which will do at least 6 knots or better in flat
water.
If your going any farther west than Old Montreal you will also have to travel through a couple of St.Lawrence Seaway locks, St.Lambert and Ste.Catherine. Once these locks are traversed you will end up in Lake St.Louis, many pleasure craft and several yachts clubs in this area.