What I understand: your office downtown, wife’s may be Mississauga, baby - daycare, don’t want to rent longer
I think Mississauga could be ideal place for you (near square one or on Hurontario upto Bristol intersection). From square one, cooksville go station is 10 minutes by bus, 7-10 minutes by car). Cooksville to union station is 27 minutes by go train. Frequency of go train is 15-20 minutes. Union station to townhall would be around 5 mins in subway. Lots of day care around square one (range from $1100 to $1900). Some have waiting, some are available. Lots of apartment and condo around square one. 1bed room may range from $1300 to $1600. 2bed room range $1600 to $2000. But any good place won’t be available for less than a years lease. Month on month rental is usually available for basements. If you are interested in this area, you may try Hillcrest condos. It’s right on the cooksville station, Commute to station would be 5 minutes walk. This condo is decent. Schools are good in this area. But it’s unlikely you would buy a house here, unless you opt for condo.
Another option could be Etobicoke near islington or Kipling station (Kipling also has GO, commute in go will take 15-20 minutes). Commute on subway will take 40 minutes. Personally I like square area better than Etobicoke.
Commute from Brampton will take 40-45 minutes on GO. But Brampton is less expensive as compared to square one area or Etobicoke in terms of rental/house price. But if you plan to buy a car, insurance is way higher than other places. Just keep in mind, insurance isn’t cheap like US. Insurance is often more expensive than the car loan (for beginners it could be around $350 to $400 per month - crazy!)
From Mississauga, monthly GO expense could be around $350-$400. If you live in Etobicoke, subway monthly expense would be around $150 (unlimited travel)
Usually rent to buy schemes aren’t good. In a new country, stay in a decent place (usually one year lease), check the ground reality and then move to your desired location.