One of the more annoying things about YOW is that even when I find a comparatively cheap flight, it gets us into MCO after midnight and it would basically waste the first day of vacation from not getting enough sleep to make it to rope drop.
Philadelphia (PHL) for some reason has flights that are consistently at about 1/2 to 2/3 the price of flying from YOW to MCO. It's a bit of a drive, 10 hours, but if you can fly in the evening PHL->MCO and return in the morning MCO->PHL then it's possible to do it without getting a hotel. If we do that this August then I estimate we'll save around $800 compared to the best available price from YOW or YUL.
The route from Ottawa to PHL is 416, 401, I-81 to Clarks Summit PA, then I-476 and finally I-95 for the last few miles to the airport. It's a fairly easy drive without much traffic except for the Philadelphia area, which is "Toronto busy".
We've done this drive many times for vacations in Maryland. In the summer the worst thing that can happen is heavy thunderstorms and construction slowdowns. Last summer there was a wicked storm in Philly which didn't affect I-476, but the side roads were so full of downed trees that the traffic was backed up all the way onto the Interstate. I would allow at least a few extra hours, or come down a day early if it looks like there will be storms or a lot of construction.
In winter there is a lot of potential for snowstorms and closed roads in the mountainous parts (roughly from Watertown NY to Allentown PA).
Far better would be to find similarly cheap flights from ROC, SYR, BTV, etc. but I haven't been able to find any this year for our chosen dates.