Being Canadian I have to say the East coast is beautiful but has much smaller employment opportunities. Real estate is cheaper generally in the east but it is always more in a major city wherever you go. Cottagers and baby boomers retiring have driven up house prices in pretty locales. If its cheap and rural-that means it is harder to make a living.
We do have teachers for english as a second language. We receive so many immigrants from around the globe it is necessary!
It astounds me how many people pick the East coast with its limited employment opportunities because it is easier/quicker/cheaper to fly to Britain. It really isn't that much further to TO when you are in the air!! And for the few times people/family will actually travel-those extra hours barely add up in consideration of priorities as to where to settle! I know people are trying to be practical but I don't think that consideration should go in to the place you will settle. Look at the amount of job opportunities and cost of housing. Many people love Nova Scotia for example but it is a small workforce. New Brunswick doesn't even register with Canadians generally as a place to go and find work. BC is beautiful and so astronomically expensive that many here simply can't afford it. If you are coming with alot of money from the UK then you have a huge leg up on Canadians.
I say Ontario. Better home prices(*outside* the GTA-greater Toronto area-the golden horseshoe). Lots of work in a variety of fields and if you focus on Kitchener Waterloo for example, you have alot of employment opportunities in those cities and many neighbouring cities. You can even commute into TO if you want. Although I am confident you don't need to to find work. Prices are cheaper here then in the TO area and Guelph is about $30000 more across the board for a home then Kitchener- but still cheaper then Mississauga, Milton, Oakville, Ajax, Pickering. Please check out mls.ca - Welcome for house prices in those cities. You could also live in Cambridge which is cheaper too. North and West of KW home prices get cheaper. Immediate towns hold value because they are so close to the city and yet has small town lifestyle-but within 45 minutes commute you get much cheaper housing. Your money would go farthest there. Stay close to TO and you have a higher cost of living. But the Guelph/Waterloo/Kitchener(golden triangle) and Cambridge area is very commutable between each city and to TO, etc. Look at a map.
There are many places to check out in Ontario away from the TO area(avoid the cities immediately surrounding as they are pricey).
Ontario is a beautiful province/lots of employment in a huge range of fields-the most diverse in Canada I would think. Skiing can be found in Chicopee in Kitchener and about an hour and 40 minutes north (Beaver Valley). If you live north of Waterloo-homes are cheaper-you can commute into the city(or Guelph) easily and be that much closer to activities-the beaches and the ski hills. For instance, I am about 45 minutes from Lake Huron, Georgian Bay, and ski hills. Also you can reach these without the crazy traffic. A small city you may like is Owen Sound. They are on the water and skihills are in their back yard. Homes you like and much cheaper. More winter. But a good lifestyle. not the hustle bustle.
Unless you are constantly going to the airport I would not base my home/life/job around it. Canadians just make plans once in a while to go to the airport and travel to get there if need be. But really it is not very often. So I would not make that a big priority as it will actually not factor into the majority of your life/success here. KW area has an airport which is now doing international flights to take the load off Pearson(TO) airport. I don't think they go to UK yet but more flights are being added all the time to meet the needs of the big population outside the TO area. So it might just be a matter of time.
Hope that helps. Please check out other posts about this neck of the woods I have posted. I have talked quite abit about it. Don't for a second think you have to settle in TO and the rat race if you come to Ontario. Ontario offers a huge array of possibilties/lifestyles that are lovely. Ontario has the jobs/companies to support this-thats why we are the major province. Ontario is full of lakes/woods and differing beauty as well.