I went to Toronto last year in May.
I decided sleep in Nigara Fall, I think most of the tourists don't sleep there.
We stayed in a hotel called Marriott Niagara Fallsview, it was expensive but the view is amazing, we can see the fall while laying down on the bath.
At night we went to a dinner/musical/comedian show called Oh Canada Eh (http://www.ohcanadaeh.com/shows/default/view/14/), it was a good opportunity to interact with local people, they put you in a big table and all the people started introducing themselves. The actors are waiters at same time, so if you ask for a drink they will serve you in between the scenes. They made jokes with the customers, so avoid the corner of tables.
The next day we went to Niagara on the lake wineries tour. It was something called tour bus but in fact it was an old citizen in a sedan tha was going around talking about everything, history of the places, harvest season, etc. At each winerie there was a like a guided tour, learning how they made the "ice wine", how taste wine, etc... I bought a box of wine, I had to make magic to put everything in my suitcase. This tour spend almost all day.
After the winery tour we went to a outlet mall there waiting the time of our bus to Toronto. They have regular buses that isn't expensive, we catch the bus in a bus station near the Eaton Centre.
Another weekend we went to a tour in French Canada (https://new.tnttours.ca/).