Oh man I would wait till spring if you can.

Check out this blog on the pending cold weather. The no it alls say we could have a pretty strong cold front come soon.
May not make it to San Antonio but I would hate for you to plant it and then have to deal with a cold snap.

mike

Here is a link that might be useful: Cold January

This post was edited by mksmth on Mon, Jan 7, 13 at 16:03

Citrus roots, and especially the "sensitive" Meyer lemon roots do not like to grow into cool soil. Wait until the soil is above 55 F. and then transplant. When you transplant, first the roots grow seeking food and water; after that the leaves and branches grow.

Thank you so much for the advice. It probably saved my tree since the weather seems to be getting colder after a warm break. Patience required.