Hi David. After surfing around this great site for a long time, I have finally joined the membership formally. This is my first post, so we will see how it goes.
I am Niagara local (Ontario side). Niagara Falls gets a bit of raw deal from a photographic perspective. It's so much more than the Maid of the Mist and typical tourist shots "off the railing". You can easily spend your two days there photographing both sides of the border and come home with some - quite frankly - stunning photos. As usual, you have to know where to go, which is, as expected, somewhere *other* than where most tourists go.
Where to start....I am assuming that if you are heading up to "Temagami" (remember, that's an "area", not really a "location", I am assuming you are doing some nature photography. You are also likely doing some urban landscapes if you are in Toronto.
1. First, add a day or two, or split the trip into two trips. This is a looooong trip to do in your time frame. It's haul from Toronto to Temagami and back. It's also congested on the highways for several hours each side around Toronto.
2. Find a local in Niagara Falls. I'm happy to volunteer (I often volunteer to host local photo walks around the area and I need an excuse to get out hiking after work), but I'm only available after 5:00 pm Thursday and Friday. Anyway, I've strated by linking a sample of the type of scenery one can shoot in one one my favorite ares, the Niagara Glen trail system (since the post seems to telling me I've gone over length already).