Congratulations on your win! I'm so glad there's finally been a Canadian winner. I was one of the OMDD winners last year and there weren't any Canadian winners. Well, I'm Canadian but I live in the states now.
To answer your question about what will happen if Disney contacts you if you're at DL, I would just let your contact at Ventura know that you'll be away during that time and she can probably let the Disney people know.
I wouldn't worry about the jetlag too much if you choose WDW. We live on the east coast and went to DL and the first day was a bit rough because our flights were delayed, but we didn't really have many problems with jetlag. We just made sure we all took a nap every day.
As for the dates that you can take your trip, there will be blackout dates and they do ask for your hotel choices but there's no guarantee that you'll get your first choice in hotel. All of the OMDD winners got the dates they requested.