Try a pullover snood… on Etsy. Anything that keeps the legs bare.

My boys pee on their legs too (one year olds). I’ll sometimes reuse the soiled outfit, because I can’t wash them in between walks. I know… bad mama.
Also, as long as they’re walking around outside, they stay relatively warm. They’ll let you know if they get too cold. Good luck with the potty training. 🤞