In making my reservation in Islas Mujeres for a slip at Marina Paraiso
I happen to asked Kevin Ball (manager) what he thought of our crossing in early December
to Galveston from Islas Mujeres and this was his reply.
It should be a fast trip North in December.
After a Northerly, East winds set in giving a good run for Galveston, Depending on how strong and how far South the Northerly traveled will determine the state of the seas.
Early Northerly's are week and don't get out of the Gulf.
I don't know how you like to sail your boat and in what conditions, but I like December for sailing North and I would pay close attention when choosing a weather
window, there's never a reason to rush a trip.
Hope I helped.
Also this winter is supposed to be a mild winter with unseason warm temperatures
and the Midwest (for whatever that's worth)