Not really any choices. I am in sort of the same quandry as you. Driving north from VT, we had found a small out-of-the-way Mom & Pop style motel where it was cheap, clean, safe and had a couple of good places to eat nearby. The place has changed hands and we don't feel as safe leaving our rig there - we usually leave from there and saddlebag. The best compromise we've found is to drive to the clubhouse in Beauceville, park there and ride out. Obviously, you have to time it so you get there at a time that works to make it to somewhere beyond to stay. St Jean-Port Joli, St Pamphile, Montmagny, or even RDL are possible overnights depending on your arrival.
We haven't gone to the Manor Lac Etchemin for about 5yrs. Too expensive and we thought they acted as if they don't really care about having snowmobilers stay there.