I live in Nova Scotia, but travelled back and forth to Ontario twice a month for a couple of years. It depends a bit on a couple of factors - where you start and stop from, and how long you like to drive. I live in Tatamagouche, I went to Hamilton, and I had two patterns - two days per direction or three days per direction. It was an 1800 km trip each way. I take Autoroute 20 towards Montreal, take Autoroute 30 Ouest at Km 95 which completely bypasses Montreal, back onto AR 20 to Highway 401 in Ontario. AR 30 will also set you up extremely well for Highway 417 towards nothern Ontario and Ottawa, btw. FWIW I always stay at truck stops, never at rest stops. I find them far safer, it's legal, there are good facilities, stores, often a quite nice restaurant, etc. Just my way, I suppose.
Going to Ontario I would stop at a large Irving truck stop just the other side of Drummondville Qu., around Km 145 on Autoroute 20. Nice big lot, a store, restaurant (hot chicken)etc, and I always snuggled way at the back in the last row. I've probably stayed there 10 nights. That was around 1,100 Km for the first day. The next day I would get to Hamilton around 3 pm, but I would often leave at 5:30 am to avoid traffic in towards Montreal. While the newly opened AR 30 bypass has fairly low traffic even at rush hour, AR 20 into Montreal from that stop often is very heavy.
If I do three days I stop near Edmunston in NB or Riviere du Loup In Qu., then Kingston in Ontario, again in truck stops. There is a good truck stop on 185 just before Riviere du Loup, just before AR 85 starts. There is a very good, RV friendly Pilot/Flying V travel plaza between Kingston and Belleville that has good fuel pumps, dump station, discount for cash or debit card, and RV dedicated overnight parking.
That's my take. On the way back home I would normally stop in Riviere du Loup on a two day trip, or at a truck stop inOntario off Highway 401 Km 720 (or so), again a big Pilot/Flying V travel plaza, on a three day trip, then stop at a truck stop at Km 433 on Highway 2 just before Moncton NB. Big lot, nice restaurant, etc.
Brian
2005 F250 Supercab, Powerstroke, 5 speed automatic, 3.73 gears.
20 ft race car hauler, Lola T440 Formula Ford, NTM MK4 Sports Racer
1980 MCI MC-5C highway coach conversion
2004 Travelhawk 8' Truck Camper