with temps in the low 40s, keep a second ball in your pocket and rotate balls every hole or two.

My guess is its not the ball, its the cold weathers effect on the ball.
Try alternating between two balls. Play the first hole while keep the second ball in a warm pocket or something. Then play the warm ball on the next hole, and so on..
Hope this helps.

Wow, that’s a strange situation. Most all balls these days are extremely consistent. I can get several rounds out of a ball and until it gets scuffed up, doesn’t feel any different and no degrigation in performance. That’s the same whether using a ProV1 or a TruSoft. Wonder if something else might be the issue? Maybe difference is swing speed later in the round or grip pressure? That said, trying any and all of the Titlest balls is always recommended.

I agree with Dale, I play the same ball until I scuff it up (usually on a cart path...) and can usually get more than a round out of it, easily, and I don't seem to notice any degradation in performance. If anything, I think it improves just a little after a hole or two.
Since you mentioned the temperature, are you compensating for that in regards to staying flexible, comfortably warm, etc.? What about your hands? I usually use no glove in the Summer, and two in the Spring. For me, having cold hands kills my sense of feel. In very cool weather, I'll occasionally use a hand warmer, the Zippo ones will go a whole round, or more, before they run dry.
Finally, I never do the ball-in-the-pocket thing. As the ball cools, it gets progressively firmer from tee to green. Not really an ideal situation. For me, I prefer it to be consistent, even if that means it's a bit firmer off the tee.
Good luck.

I think it is a temperature issue not a ball issue. Modern balls are made so well any ball should last until it gets damaged. Being in WI, I can confirm balls feel harder when it is cold out. A softer ball may feel less hard after a few holes but may feel too soft for you for the first few. My vote goes to rotate two balls from your pocket every other hole.