So it has finally started to get a little cold in Texas and when the temperature drops to about 35 degrees F or less my power locks refuse to work first thing in the morning. I can unlock my car just fine using the emergency procedure to get in and the car starts up just fine without any problems (so I'm thinking it is not a battery issue). Once I get to my destination (about 10-15 min) I can lock my car using the power locks. Any idea what might be causing this odd behavior?

Water gets in the door and can gum up the latch and lock assemblies. The viscosity of the grease used on the moving parts also changes when it gets colder, and years of people spraying silicone in the area can also gunk it up. I would remove the latch assembly, clean and lube it.

Also, another thing to remember is that although it is not supposed to happen by design, water can get into the lock actuator itself.

How do the seals around your door handle look? Are they cracked?

If they are severely cracked, they can let water and gunk in that will clog up your locks.

So it has finally started to get a little cold in Texas and when the temperature drops to about 35 degrees F or less my power locks refuse to work first thing in the morning.
You might want to check the health of your battery. When temps drop, odd electrical gremlins can sometimes be traced to a weak battery. The next time this happens and BEFORE you start the car...once you get in do a TEST #9 (if your OBC is unlocked) and see what the battery voltage is. If the battery is reading below 12v...that could be your problem. At 11.89volts...the battery is a 0% state of charge.

In your scenario, if the battery is low but still strong enough to start the car...after you arrive at your destination, the battery has recharged itself, so the door locks work with no problem. Just a thought. :)

How do the seals around your door handle look? Are they cracked?

If they are severely cracked, they can let water and gunk in that will clog up your locks.

Not only check the gaskets & seals around the door handle...also check/lubricate the weather strip (#5 in diagram below) along the bottom of the window where it slides down inside the door. That rubber weather strip gets assaulted all year long with soap and cleansers...yet rarely get lubricated/rejuvenated. That strips helps prevent excess moisture from entering the cavity between the door panels.

http://www.bmwmobiletradition-online.com/bmw/diagrams/s/r/6.png

The next time this happens and BEFORE you start the car...once you get in do a TEST #9 (if your OBC is unlocked) and see what the battery voltage is.

Qsilver, how would I do a TEST #9?

Qsilver, how would I do a TEST #9?

You have to UNLOCK your OBC first. This consists of adding up the sum of the last 5 digits of you car's VIN. Once you have that number...proceed to TEST #19 and enter that sum.

Once you go to this site (don't worry about it being for the e32...the e34 uses the same OBC): http://home.iae.nl/users/bts/obc.htm ...read the instructions on "OBC Knows 2 Modes" & "OBC Knows Two Hidden Keys". You will use the 1000/100/10/1 buttons to enter numerical info...and to access the TESTS. Press the 1000 & 10 buttons to begin accessing the TESTS

http://home.iae.nl/users/bts/images/Test.jpg

Once the OBC test #19 says FREI...you can do TEST #9 (anytime you want) or any of the other TESTS. To check the battery or any of the other TESTS just press the 1000 & 10 buttons...then press the 1000/100/10/1 buttons then the S/R button to begin any TEST you'd like to see.. The OBC will stay unlocked until it looses power (battery disconnect)...a lose of power re-locks the OBC.

BTW, with the engine running, TEST #9 reveals the voltage put off by your car's charging system...this is a way to tell if the alternator is dying on you.

BTW, with the engine running, TEST #9 reveals the voltage put off by your car's charging system...this is a way to tell if the alternator is dying on you.
I'm getting about 13.8 with no accessories on. 13.3-13.7 with lights/heater/defroster, and at one point it dropped to 12.9 for a split second. Should I be worrying about my alternator? Revving the engine to ~800 from idle brightens the lights slightly.

As long as you stay above 13.5V, regardless of how many accessories you have on, you should be ok. Ideally, you should be in the 14.0V range, but staying above 13.5v is important. If you are consistently below that level, you should have your alternator (or at least voltage regulator) checked. Those numbers tend to be a little bit lower at idle, so I'm talking about staying above that threshold under normal driving conditions.