Quote Originally Posted by richard ide View Post
Waxing the glass will prevent fogging.
Yes. There are products out there to prevent fogging. Rain-X makes one.

If treating the glass isn't enough, you might try to find an oversize drinking straw (sometimes called a "wide" straw) as an easier to carry and use alternative to a snorkel. An ice cream shop might have just the thing for milkshakes and other thick drinks.