Toronto - Niagara to YYZ on a Tuesday morning

I'm scheduled to take a noon flight from YYZ on a Tuesday in December. Thinking of spending the previous night in Niagara (partner is a lifelong Canadian who has never spent any time in Ontario other than an overnight transit near the airport). I know the drive time to YYZ should take 2 hours but we have a car to return. Assuming an arrival at YYZ by 1030, would there be a problem leaving Niagara at 830 or would we have to leave earlier?

The problem is -- December. Normally, the drive is no problem and you're going after rush hour. So check the weather forecasts and radar before heading off to Niagara. If a snow storm gets in the way, you don't want to have a time point to make. The ride on the QEW is very dull. I had my GPS on for my most recent trip and the dummy kept telling me to stay on "Kyoo" for 90 km. It also mixed up the Gardiner Expy and the QEW in Oakville - so look at a map. The route is very simple - use 401-403-QEW-420 and reverse.

Thanks. I do have the weather situation in mind and have a backup reservation to overnight near YYZ in case of inclement weather. So 2 hours to YYZ assuming dry pavement is a good estimate to work with?

So 2 hours to YYZ assuming dry pavement is a good estimate to work with?Yes, that should be a reasonable time frame outside of rush hour and no inclement weather.

If you don't mind paying toll (expensive - probably more than $20) then you can take highway 407 from Burlington. This will likely speed you on your way from Niagara to Pearson.

407 is fully electronic for toll charges. If you're in a rental car, the agency will mail you the toll charges when they receive the bill.

Toronto to Niagara is roughly 130 km. 2h under good conditions is plenty but obviously snow / inclement weather could be a big factor for you.