We usually try to go for an aparthotel instead of a hotel room as it's much more accommodating (usually would come with a functioning kitchen and washing machine). They're the same price or cheaper than a hotel room normally. Otherwise you can get the milton cold water sterilizing tablets. And haven't tried this but maybe you can get a small beach cooler and store the milk on ice in it overnight?
We took a collapsible basin and Milton sterilising tablets to sterilise bottles in the hotel
There is a really good group on Facebook called travel with babies! We’re currently away and have taken a collapsable bucket and Milton tablets. We also have a fridge in the room.
We took our usual steriliser (cold water method) and just packed it, we used local tap water to sterilise. Luckily our room had a fridge but we would have paid for one if it didn’t x