If your DH isn't close to his parents, and doesn't understand how you feel, that's a huge red light for me. What happens if you move, then really, really miss your parents? Will he be understanding about returning to the UK, or will he resist it? This situation can get very strained, if not outright awful, when there are kids: you can't unilaterally take them home yourself.
Also, beware of minimizing the move's impact. Be honest with yourself, if only to avoid shock: it's going to be a huge change, if your parents are very emotionally and practically involved in your UK life. Skype and emails aren't the same, and Canada isn't close. It's easy to glance at ticket prices and think 'that's not too bad', but prices fluctuate, organizing time off work and other travel-related considerations is a hassle, and visiting/being visited when you live far away is intense, compared to more everyday contact. Would you realistically see each other more than once or twice a year?
Finally, I think the ostensibly cheap price of property in North America can be a bit misleading. I don't know about Canada, but in the US there are often unexpected, unfamiliar costs to home-owning: expensive property taxes, higher maintenance bills due to extreme weather conditions, shorter-lived structures that need repair more frequently, and high seller costs which means you really lose out if you buy then sell too quickly. Obviously depends on the region, but a lot of expats get burned. So don't just go by sticker price alone.