Historical "average" temperatures for mid-February in the Big Bend area (Terlingua) is highs of 74 and lows of 40.
https://www.accuweather.com/en/us/terlingua-tx/79852/february-weather/341053
That's an average, so that would mean cold mornings but nice days and good riding as long as you brought the right gear to layer on and off as temps changed on you. I've been there in late Feb and early Mar and it was nice. But you never know, right? Could be a 'cold' spell comes through while you are there and you freeze your *** off or the temps get into the upper 80s and you are seeking shade and water. If you are just looking to play the odds and go see the area, I think mid-February would be just about right. Go for it! (By April, it's getting too hot for my tastes, so Feb/Mar are the times to go.)
For more info on what to see in the Big Bend area:
https://www.texasmonthly.com/travel/big-bend-made-easy/
For "road" rides, you have to do RM-170 from Terlingua to Presidio and back. It is just too fun and too scenic to miss. In the park (BBNP) the road up to Chisos Basin is fun and the views up there are great. Plus you can eat at the restaurant up there, which is nice. Next, take the road to see Santa Elena Canyon; one of my favorite places in the park. Your 'stuff' is pretty safe on the bike there, too. Boquillas Canyon is also a nice ride and a pleasant hike, but I would not leave ANYTHING on the motorcycle there. The Mexican nationals cross the river frequently in that area and even the cars get broken into and 'relieved' of their cargo, which is a bummer.
I see DRZ is part of your name, so I'm guessing some dual-sport might be on the agenda? If so, the River Road in BBNP is a good dirt ride. You get on it just 2.6 miles NE of Castolon off the Ross Maxwell Scenic Drive. You take it to Rio Grande Village and it is about 68 miles of dirt. But it will take most of the day to do it, so plan accordingly. Take your time and don't push it! The one time I rode it (on a KLX250S) a group of KTM riders were hauling-*** and one crashed and broke his collar-bone (and arm?) he was stuck out there for over 5 hours waiting for an ambulance with 4-wheel drive to come get him and haul him out. Then I think the put him on a helicopter to get him to 'real' medical care. NOT CHEAP! So, I repeat, take it easy, enjoy the ride, and don't crash. Best to go with a buddy if dirt roads are on the agenda. It is a no-joke, you are far away from everything WITHOUT CELL RECEPTION kind of place. Even the park rangers have to rely on satellite phones.
Good luck. Hope you go and have a great time.
Michael in the Texas Hill Country
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