Well as far as travelling goes, the hubby and myself have made the drive from Toronto to Calgary (about 3500 kms) about eight times now. It takes us about two days or so depending on road conditions and how often we stop. He has made the drive in less than 24 hours, but he was a horny psychopath at the time. Last time we came across we did it with both kids (our daughter was a year old and our son was almost three at the time) and it took closer to four days, because of frequent stops etc. (we also had three cats in the car too..joy!) I would say from coast to coast it would be about 5-6 days if you were driving at max speed limit and the road conditions were ideal with a minimum of stops... possibly more. It's VERY tiring though, so you would probably want to give yourself an extra day just in case you need a bit more rest towards the end..because the last leg of the trip is always the most gruelling.
It's definitely fun to see your country from the ground, up close and personal though. Make sure to take a camera