LOL, please don't take me as an expert, I have never fished anywhere in Ontario before the June bass opener, and the waters I have fished there as destinations are extremely limited, the Kawartha lakes never made it on the list.
Water depths? Pike spawn early, if you are familiar with the lakes? look for areas that may be spawning areas for them or with early weed growth. Shallow coves, bays, flats with deeper water access, my idea would be to keep a lure running just above the weeds or shallower areas, with cooler water temps they probably haven't moved to far from them after the spawn.
A spinner or spoon doesn't seem like a bad choice of lures, but mixing in crankbait or lure that has a defined running depth might not hurt?
Our northern pike fishing is very limited here in Ohio, there are areas off of Lake Erie were I had a reasonable expectation of hooking one in April and early May, but as soon as the water started to warm they were gone.