Bleach is cheap. I wouldn't save it. We have bleach for use after storms. I've had it evaporate out of the original Clorox bottles! If it can do that, it can get out of about anything.

I buy only super concentrated laundry detergent. Little bottles that don't weigh much and are easy to tote and store.

In any case, I would only store enough detergent to get your started for your next visit. What else is in that storage box that could get ruined?

Someone else who posts on FT uses that service in Florida. Perhaps she will see this and add her opinions.