tweety, i think you are eatingmy favorite ice cream in your new avatar...purely decadent coconut milk cookie dough, or no? that stuff is the best.

Eating out is a challenge if you dont get to pick where to go.  Chain American restaurants are horrible places to try to eat.  Bland pasta and marinara or iceberg salads.  Blah blah blah!

But as you found out Mexican is so doable.  You can probably also find burritos with rice and beans in them.  Some places even offer veggies in those!  Just always remember to ask for No cheese and No sour cream and send it back if they forget and slather it on.  Never be afraid to do that.  If my plate comes out askew, I apologize and say "Please no cheese, no sour cream.  I'm allergic to dairy."  That usually fixes things right up!  Yes I exaggerate but I would rather do that then get sick from them slipping me cheese. 

Oh and always open up that mystery burrito/veg burger/wrap/fried mystery first!  That way if it looks wrong or meaty you can have someone taste test it before you do.  I had one place swear up and down they brought me a veggie burger but the manager took one look and said "That's turkey" while I swore it was some form of meat.

Places I have good luck in: Mexican, Indian, Chinese, Japanese and occasionally Thai.  Just speak to as many people as possible who work there.  Be clear as to what you want "No Meat. No Dairy." Throw in a "No Fish" if you have to.  And if they give you crap like "Depends on how vegan you are because we season all our food with Chicken Broth." they are obviously a crappy restaurant to begin with so no loss there.

My only holiday advice is cook for yourself.  Its work and can be hard to get family or friends to not mind you bringing your own meal, but its worth it to me.  Plus you can blow people away by bringing awesome vegan pie or cake!