Hiya am having the same worry. I am gonna ask my Mw but to save raff with steriliser etc nip into boots, they do starter packs of premade milk from sma, cow & gate and aptimel, I plan on getting a couple of the sma ones, 8 feeds for £15 I think
You could buy the cartons as any unused can be used for night feeds. Mam bottles are also self sterilising so u will be able to do that provided there is a microwave in the parent room. So u could get away with only taking two or three bottles.
Some hospitals have cold water sterilisers available in a kitchen area, but that can be away from you. Not ideal if mobility is an issue or in the middle of the night. There are usually fridges to store cartons etc but tbh I would go with the starter packs. Even in my small Boots I got an Aptamil one, 6 x 90ml bottles with sterile teats. Screw them on and that's it. I've packed a box in my bag and if I end up having to stay in for a while like I did with Dd, will send DH out for more. They weren't cheap but honestly, for convenience, it's only likely to be for a few days at most until you're home.
Check with your mw but other than very basic facilities, our hospital provides nothing at all, no nappies, wipes, and definitely no formula unless medically needed. Go prepared and it will probably all work out fine!
We used the starter packs from Aptimil & they were brilliant, if expensive. No need to make up formula or sterilise anything. And the bottles have measurements on so you can see how much has been taken.