Power shut down - what happen to freeze milk

This is quite a random but important question. Sometimes HDB have this power shut down for the whole blk for few hours whereby all electricity will be cut off. Which means, including our fridge and freezer. What if i have quite alot of frozen milk stash stored in my freezer? To save the milk, can i pack it in cooler bag with reusable ice bags and rush to my mum’s place (30 mins away) and store it back into her freezer for few hours ? And once power is back at my own house, i pack again using the same step and put back to my own freezer ? Or its not advisable? Any way to save the milk from going to waste? If i cant refreeze it in freezer and put in chiller instead, baby wont drink all the milk stash, what will happen to the remaining? #firsttimemom