" No issues with driving a couple of hrs if needed."
If that is the case then Get your backside down to Long point area (1-1.5 hrs sw of oakville) for a day. Alot of the previously mentioned areas will still have good sightings. However by that time the ice is gone an birds are scattered or left on migration. (the liftbridge Peregrines obviously will still be there)
Long Point Fisherville area from mid march to late May is well worth the trip. End of march there will be species there like Tundra Swans (prrbably a 1000+ still loitering) mid march is when one can see 5000+ Tundras, Breeding Sandhill Cranes and Bald Eagles, 10,000+ waterfowl including ALOT of Canvasbacks (thousands), the yearly 1-3 Eurasian wigeons, One can easily get 20 species of waterfowl down there in morning. Early migrants like Tree Swallows, Greater Yellowlegs, Wilson's Snipe, Little Gulls, Yellow-rumped and Pine warblers, etc. and etc. As much as I live inthe local wetlands of oshawa area in spring, I make sure I get to Long point at least 3 times a spring. Never dissappointed. Also the carolinian forests around long point are quite impressive as well.
Late March In fisherville will have breeding Screech owls, Bald eagles, Great horned Owls, Turfted titmice, eastern bluebirds, Wintering bird such as Red-headed Woodpecker (irish line and river road), Short-eared owl, both phases of rough-legged hawks and golden Eagle should still be around. and the RBwoodpeckers now are in every woodlot down there it seems.
Closer to oakville other good spots are the beamer C.A. Hawkwatch in Grimsby. In the right weather it is quite enjoyable.
NW of Oakville is Mountsberg C.A. the large shallow reservoir is a great spot for migrants from late march to early may.
Cheers
tyler