Another vote here for making them up in advance in future. Although it’s not advised, if you read the NHS website carefully you can find advice where you do just that:
‘What if I need to transport a made-up feed?
If it is not possible to follow the advice above, or if you need to transport a feed (for example, to a nursery), prepare the feed at home, cool under a running tap or in a bowl of cold water, and cool it for at least 1 hour in the back of the fridge.
Take it out of the fridge just before you leave and carry it in a cool bag with an ice pack, and use it within 4 hours. If you do not have an ice pack, or access to a fridge, the made-up infant formula must be used within 2 hours.
If made-up formula is stored:
in a fridge – use within 24 hours
in a cool bag with an ice pack – use within 4 hours
at room temperature – use within 2 hours’
We just did that without the transporting bit.
Either that or buy the pre made formula. It’s expensive but SO much easier, especially in the first couple of months when you are getting the hang of things and the feeds are constant.