As for pot, the only time I've smelled it (and not infrequently) is in the smoking areas because several of our friends smoke (cigarettes) so we stop there for breaks.

And its usually pretty sweet smelling, not the rancid smelling stuff that the vagrants in front of the public place that I work smoke, so we don't comment and let them enjoy their vacation.

(There's usually a difference between different kinds of cigarette smoke, as well as most other kinds, the cheapest stuff always seems to be the most offensive, which is why I always have a hard time walking around the Strip at Las Vegas since it seems like everyone there smokes $1 packs. I've gathered that Disney smokers of all varieties don't tend to buy the cheap stuff; often I smell a mixture of cigarettes, cigars, cloves, and a more illicit substance. I'm a non-smoker, btw.) If you're not a smoker you're much less likely to encounter it, but I wouldn't recommend having your kids hang out near the smoking area regardless of the substance because of the second hand smoke.