You’re on the right track at least. I found these but too small. Playtex Baby Nurser Pre-Sterilized Disposable Bottle Liners, Closer to Breastfeeding, 8 oz, 200 Count https://www.amazon.com/dp/B06XCP5RSF/ref=cm_sw_r_cp_api_i_HVAzFb3C9ZBAD

Ziplock bags should work, but in moving vehicle they would be bounced around the fridge and likely break.

The ziplock bags can be contained in a larger (but not too large) rigid container that is re-usable because the container won’t get dirty.
This would keep them from bouncing around too much.

But I thank you for providing an actual solution.