Upvote:0
I am not a travel guru or anything, this is my personal experience.
We were traveling from NY up to Canada, took us a bit more than a month. After staying in Canada for a week, we did not get our stay renewed when we reentered the US. The same thing happened in mexico.
Upvote:10
This is a very risky strategy. There is an explicit provision of the VWP that allows border guards to readmit you for the remainder of your original 90-day stay if you travel to an "adjacent territory," which of course includes Mexico. This is for the express purpose of preventing "visa runs"; that is, it is supposed to stop people from doing precisely what you're trying to do.
So, for example, if you entered on October 5th, and were admitted until January 2nd, and you go to Mexico and return on December 28th, you are most likely to be admitted until January 2nd. If you indicate plans to stay in the US after January 2nd, you may be refused admission.
If you want to go out in the hope that you'll be given another 90 days by an inattentive border guard, you can always try. If your new stamp indicates a departure date of March 27th, then you are probably fine to stay until then. If you're prepared to leave the US by the original deadline, and they don't give you any extra time when they readmit you, then there's nothing lost.