We have kids your age and have been to Mexico Europe and Costa Rica. Going to Costa Rica again this year and wil stay at all inclusive for home base and we rent a car to get around and see stuff. Just make sure you check the hotel distance from airport as some hotels are four hours away. Also bring a backpack carrier. Totally recommend Costa Rica with kids! Just ignore the dirty looks people give you when boarding the plane with small kids

I'd stick to a US city for this year. But Montreal is fun too. We took our almost 2 year old and had a great time, and I found lots of good vegetarian food. Quebec isn't far either.

Acela to New York City!

I like the Montreal idea best (but I am biased, as I hate the beach and beach + toddler is the opposite of vacation for me). It's been a while since I went to Montreal but I don't recall having trouble finding veggie options there. I like city vacations for toddlers - lots of things in one place, so you can easily go back for a nap if needed.

I like both Montreal and Vancouver. Lots of options for kid-friendly activities and fun for the adults.

St. Thomas/St. Johns? There's also Vancouver. Borderline five hours

Personally I think Costa Rica would be more enjoyable when OP's child was older.

You can make it to Costa Rica in about six hours, even with a layover. I'd look there or Puerto Rico.

we have a kid around the same age and recently got back from grand cayman. Direct flights from Dulles. Not lots of culture (there are a lot of things to do and museums etc), but very safe. There are a number of hotel and condo options. cayman was quite expensive (especially the food), but definitely doable on your budget. (airfare was about $500/ person I believe; we rented a car-- which I would say is a necessity with a toddler, which cost $350ish for a week)

I agree that Puerto Rico sounds like your best bed. Bermuda could work too, but there's not necessarily a lot of "culture."

There is bacon fat in almost everything in New Orleans unless you go to a veggie-place or a menu is veggie specific. You have been warned.