We lived in Ontario for two years.
The weather is crazy. You will spend a fortune on outdoor clothes/shoes and two sets of tyres for your vehicle. It is lovely though! Hot summers - make friends with people with lakeside cottages. Cold winters - take up skating and skiing.
Don't get sucked into the idea that you need to buy a huge north American home. We did. Property taxes were crazy, redecorating is like painting the Forth Bridge, heating bills are only going to rise, garden expenses are big on those huge plots. Don't go wild. There are some great apartments in Toronto :)
People take 'disaster preparedness' seriously and keep lots of toilet rolls, Kraft Dinner and bottle water in their basements.
Kraft Dinner is vile. If someone offers you 'macaroni cheese', say no.
Real cheese is weirdly expensive and very dull. Buying artisan stuff from Quebec is OK, but you will require a second mortgage.
Clothes are awful. But the women are very well groomed. I looked weird in my designer clothes yet with shaggy eyebrows.
In Ontario, you can only buy alcohol in government licensed stores. You will struggle to buy a bottle of wine after 8pm on a weeknight. Remember this when you have just got off the plane and travelled to your new home and want to celebrate. Do not drive around the neighbourhood looking for an offie or corner shop!
We had a fun time there, but we were glad to come home.