Using a zip lock to keep out the air probably will not matter. More important is overall temperature. Being in El Paso, you probably do not want them sitting around for several seasons it the heat of a garage or car trunk. The modern solid balls handle temperature much better than the old wound balls but over time, extreme temperatures could impact the materials. Keeping them in the air conditioned and heated house should be all you need to prolong their life for several years if needed.

Solid core balls have a pretty long shelf life. Balata balls with rubber band windings will decay both in size and response.
Room temperature is fine. Freezing temperatures don’t alter the ball much but don’t actually extend the life. Car trunks that can reach 120-150 degrees are the most destructive. Clubs as well.
At room temperatures, they are stable long after most players will cycle through them, like 10+ years.

Well DO, here in Phoenix when the outside temps are 110, the trunk of the car is not the only place of concern. Our garages reach 120+ and the HOA does not allow us to leave the doors open so clubs, balls, grip tape, all suffer from our summers. I recommend anyone in a warm weather city try not to leave them in the garage unless they have added some cooling system.

What kind of golfer leaves his gear in a garage???
My wife keeps telling me the dining room is NOT meant for storing golf gear, but I disagree.
Arranged properly, the ProV1's make a very attractive centerpiece for the dining room table.

I agree with your assessment, but I use the finished basement. Big advantage, the club upgrades are less noticeable so I don’t have to explain every change or why I need 10+ boxes of balls. Oh, and the climate is 65-72 F year round. Even here in WI the garage will often exceed 100 F.

Haha! Right, you may have grabbed up the last non-golfing wife that wants their house covered with golf stuff. Many a garage "man caves" out there. Had one in San Diego where the weather cooperated. Lots of golfing residents here have their own driving golf carts which have a garage parking area. Hard to load and unload every day so most everyone just has to deal with it. Thinking about adding a separate air conditioner but currently using a large industrial fan that is doing a pretty good job. All the other heat sensitive stuff and extra ball stock is in my office room, which does get to be decorated in all my golf stuff.

My "spares" are stored inside in climate control. The clubs when not in use are the focal point of my home office. Never thought of the zip locks and really didn't think how and where made that much of a difference. After all, most of mine aren't being stored long enough for damage. Unless you dig through the woods at the local course.

I keep mine on a shelf in my mancave/office, around 74*. Where I keep my clubs.

Mine are kept in my house. Never exposed to extreme heat or cold! Kept at a constant temperature 60-70.

I have a home office. I store my golf balls on a shelve in the closet just for my Pro V1’s. My clubs are brought into the office as well. Have a putting area setup to get a little practice in.

In my office on shelf and out of the sun... !

I always keep my clubs and golf balls in my basement where is 60-70 degrees down there.

I keep mine in a cabinet in a finished basement.