Spend more of the winter further south, December can be a dice roll in the south including Texas, but mid December at elevation in New Mexico is likely to be cold, to put this in perspective I got caught by an early season arctic blast in eastern Arizona in 2019 with overnight lows of 12F the last week of October, sure that is early, but you are looking at being in that region 6 weeks later than I was. Even Galveston can have freezing weather in late January / early February (Galveston is 160 mile drive from our house), though it rarely stays below freezing for more than a few hours, and rarely for more than 1 day in a week.
Much the same can be said about Dallas the last week of February, might be cold, though March 1st would be much safer for weather, most years the worst of winter were we live in western Louisiana occurs the last half of January and first 3 weeks of February, some years we see lows only reaching down to circa 28F in the overnight hours, average year will see a couple of 24 hour spans below freezing, but barely, perhaps every 5 years we will see overnight lows below 20F, and up to 48 hours in a row below freezing, record low here is 12F which we have hit twice in the last decade.
