Flying out of Pittsburgh next week to Orlando for the first time!
Long story, but we were hoping to go down to Universal with another family, and by the time they knew they could get the time off, all the flights out of Pearson were $800+. So onto Google Flights I went - checked the usual options like Buffalo and Detroit - nothing great. So I thought - if we were willing to drive 4 hours to Detroit, how 'bout 5 to Cleveland or Pittsburgh?
And lo and behold ... I actually found a $100 (CAN) ROUND TRIP non-stop! But the times were poor, and it was on Spirit, which charges for everything ... so we went for a $225 (US) flight on Southwest. Heck, the free baggage alone paid for a night at an airport hotel - parking and shuttle included. The other family will be saving over $2000 on the trip.
Of course, the OP's question is about the drive in January. I've done that stretch of I-90 along Lake Erie at that time of year several times, and with the constant threat of lake-effect snow in that area it is a bit of a crap shoot. The good news is if things are dicey you can avoid 90 and head south from Buffalo, away from the lake, and then west over to Pittsburgh. Not the shortest route, but a good back-up just in case.