CO/AZ has a fare of C$1222 All-in, but on the outbound you have to change from EWR to JFK on a 6hour stopover....

If Flying out of SYR is an option (2.5ish hour drive from Ottawa), there is a C$898 All-in on AF/DL, or if you want *A there is a C$918 All-in with LH outbound, US inbound...

Last time I was at SYR, I think parking was $8/day or something, you can probably check their website or call to find out, but also a lot of the airport hotels allow up to 3 or 4 weeks of free parking if you stay one night, so oftentimes it is far cheaper (and easier) to drive down the night before, get a good sleep, then take a free shuttle or cheap cab ride to the airport.

If you're saving $600-$1000 on 2 tickets (flying from SYR as opposed to YOW) these extra costs are still far worth it.

Of course if they don't have a car then it's a problem........

Hope this helps though

-mike