I think they will be okay with such a short trip of 3 days. As long as they aren't getting overheated, they should be fine with what they eat/drink at the hotel overnight.
We did a 9-day move across the US with 7 cats and they hid during the day as we drove and only came out from under the blankets (they burrowed under them) at night. Oh, they were transported loose in an RV with access to water, food and litter 24/7. Only one cat was comfortable with vehicle travel and he spent most of the trip on the dashboard watching the traffic and scenery.
Once you get settled into the apartment, I bet they settle in pretty quickly. I think they will appreciate not being in the carriers, not moving, having their familiar things/smells and furniture around them AND...you being relaxed once the trip is finally over and you are 'there'. Do put them in one room of the apartment as you get things settled so they can have a 'safe room' and let them out into the rest of the apartment for short bits (until you see they are okay) to get confident with exploring. If the apartment is small-ish, you may only need to put them in one room for only a day, or overnight, before you can let them explore unassisted.