Ooh, I just found another option on well.ca

Organika pink lemonade electrolyte powder

Not exactly what you're looking for, but Wake water has a couple powdered zero sugar electrolyte (and energy) drink mixes, and Roar has some low sugar berry lemonade hydration/antioxidant powders.

I personally do not like drink mixes, I try to do as much as I can DIY. I just did a search on ecosia and found https://tastesbetterfromscratch.com/strawberry-lemonade/, I have made a few things posted on tastesbetterfromscratch but I really prefer Allrecipes then a gain Lemonade is not my jam.