
Umm, don't a lot of the people in Canada (except for the east side) already speak English? All of my Canadian friends speak perfectly good English. Besides, there are plenty of TESL jobs in CR. I would prefer to winter there if I had the choice.
As far as Tenerife goes, you can expect to find all of the Canary Islands overrun with British, European and Scandanavian tourists. Even though the islands belong to Spain there is not much that is "Spanish" about them. On the plus side, the weather is fantastic, the beaches are topless and there is some P4P action in some of the bars at night.