Well, here I go jumping in on something I should probably leave alone, but...
First, let me join in on the same advice everyone else has given you. Don't have that many drinks and a weapon near you. As you will see in a minute, I think you would be okay legally in the situation you describe, BUT I always advise against being a test case or getting near the gray area of the law.
Second, I think there is some doubt about how much you will need to be legally intoxicated. At this chart, it shows a 200 pound man would need 5 drinks in about one hour to be intoxicated. Obviously, this is just an estimate and many factors will affect your BAC. Things like your general health, metabolic rate, and the amount of food in your stomach will affect it. Note that the chart is based on all drinks being equal - 1 oz of 100 proof liquor, 12 ounces of beer, or 5 ounces of wine. I post this just to give you a very rough estimate of what your BAC will be.
http://www.drunkdrivingdefense.com/general/bac.htm
Now, as to whether or not you will be committing a crime, it is hard to say. I disagree with TXI on whether or not you can be legally intoxicated, but I not ehe used the word drunk which has no legal meaning. Chapter 49 of the Penal Code establishes that you are intoxicated at a BAC of .08, no matter how well you are in possession of your faculties. Since there is no legal definition of intoxication in Chapter 46, I believe the rules of code construction and definitions would make the same definition apply. Thus, if you have a CHL and a BAC of .08 and a weapon, you are violating the law.
Now, it is very rare that I get to disagree with Charles on the law, but I believe he analyzed the situation slightly wrong. You will not need to worry too much about being in violation of the Public Intoxication laws since it requires you to not only be intoxicated, but also to be intoxicated to the point where you may be a danger to yourself or others. That is a much harder rule to prove. BTW, this is where most officers get the idea that there is no such thng as legally drunk. You can be drunk and not a danger and you are not breaking the law. They forget that the law for CHL just requires you to meet the definition of intoxicated and in the newer Penal Code, the .08 limit applies to all things. This changed when DWI was moved from the Transportation Code to the Penal Code.
There are two ways this could be actually handled by the officer on the street, and they will differ based on your behavior.
So, here is how I think the situation would be handled, if you have the sense to behave when you are intoxicated. Your wife is driving and has had no alcohol whatsoever. She gets stopped for speeding or something like that. I doubt the officer would ever ask to search the car, but assuming he did find the gun, your wife would claim ownership and you would keep quiet. The officer would apply the new definition of unlawfully carrying where she can have the gun legally and nothing would happen to either of you. This same would apply for other ways the police find the gun, such as a traffic accident. In real life, if you are both cooperative and the gun is there legally for one person, I doubt there would be a problem.
But, there is the other possibility. You are actually drunker than you think you will be and cannot keep your mouth shut. Your wife gets stopped or you have an accident or somehow come into contact with the police. During the contact you say something that gets the police officer interested in you. He identifies you and finds you have a CHL. He is also a little irritated since most cops get fed up pretty easy with drunks. Now he thinks there is a gun in the car and starts to search. He finds the gun. He decides that since you have the CHL and your wife does not, the gun must be yours, no matter what she says about it being her weapon in her car. You are intoxicated while carrying a weapon. You have a CHL. The fact that the gun is in the car which you own (community property rights, after all), the officer wants to book you. He knows that he cannot book you under 46.02 for UCW, but he also knows a CHL cannot have a weapon while intoxicated. He books you under 46.035 for carrying while intoxicated. Now, he will testify in court that he believes you were over the legal limit but he uses SFST procedures to get the BAC. He will not give you a breath test since that is limited to driving/boating/flying type offenses. You go to jail, get booked, get bonded out in the morning.
You will probably win in court, though I do not guarantee it. The law for 46.035 does require you to be carrying under the authority of the CHL, which is not true in the car, but it will take a court case to prove that point.
This is why I come up with the advice to drink less than you were thinking or to leave the weapon home. Worst possible outcome I can think of is that something happens when you are driving home and you get in a shooting. The alcohol would certainly not help the situation. Look at the comments here on the old man who shot the burglars just based on his mouth.
