Do you need Air care to renew you insurance in BC? If so would they accept an emissions test conducted in Ontario?
Unless you are going to move to Ontario I don't believe it's your best option to insure and license your vehicle here. if the BC licensing or insurance will accept an Ontario emissions test, if its needed, then i would highly recommend insuring it there after getting it tested here. When I moved here from Manitoba i was told I would have to re register every thing i owned with in 1 year after i moved to avoid paying sales tax under a provision of the settlers act. I would bet that unless you are moving here that the licensing office would collect the provincial sales tax on the value they think your vehicles worth before they would license it, even if you can find a way to arrange insurance.
I would pursue finding a way to keep it insured and licensed in BC over trying to license and insure it in Ontario if its at all possible.
You really have to get another driver's licence..?!?

I don't believe its a case of getting another license. it would be a case of exchanging the BC license for an Ontario license, which would only be required if you've moved here from another jurisdiction and you would have to do with in 60 days of changing your residence. If was only vacationing at his cottage for 1 month or two it wouldn't be needed, unless it becomes necessary to insure the car in which case an exchange back to a BC license on the return home would also be necessary.
I would rather drive across the country twice a year as stand in a drivers license office twice a year. if BC is anything like my last visit to a license office here the drive would be over before you made it through the line up.