We are to mexicans, it is possible to visit Lhasa just the two of us?

If just two of you want to travel, it is impossible. If you want to go, the Tibet Travel Permit is need and it is issued under the condition that the tour group is 5 or more people
with the same nationality, traveling from the same city to Lhasa and arriving in Lhasa on the same day. So you need to join a tour, if you want to go.
Recent, even if you meed the requirement above, it is still little bit difficult to get a permit, so it is hard to say whether you can get one next year. I suggest you to wait and see. You can keep attention on TravelChinaGuide. com to see the latest news.

thank you very much for your support