Question about hotels in croatia for family of four - help!

Croatia isn't a place where I'd try to use hotel points. In many towns, in the best locations, there aren't many proper hotels. instead, there are many more apartments and "sobe" (B&Bs or private rooms, basically). The exception might be Zagreb (I used hotel points there to stay at the Westin, many years ago, because it was cheap and I had the points). Nothing wrong with using points where it makes sense, but in coastal towns like Split and Dubrovnik, for example, you might fine sobe that are in better locations. I wouldn't want to stay far from the center in a hotel just because it you can book it with points.

Try the website booking.com and use the map feature and see what you can find. They do list the size and occupancy of the rooms, too, in general.

Yes, definitely use the sobe approach. We were able to stay in a great apartment in Zagreb, 5 blocks from the main square and close to the Botanical Garden, for 45 € in June of 2017. It had 2 beds in a single room, but no breakfast. We stayed in Split in another nice apartment in 2011 for maybe 90 €. But we use money, not points.

In Europe you are expected to disclose how many people will be using the room. You may get turned away if you show up with four people after having booked a triple.

In Croatia you may be able to find very reasonable lodging and keep your hotel points for use in the US.

In America, a double room is often 2 double beds - this is not the case in Europe and a triple will only be large enough for 3 people. You need to be upfront about the number of occupants, as you risk being turned away when you arrive there. You can't have a 10 and 12 yo sharing a 2ft 6 inch or 3 ft wide bed.

Most people going to Croatia book apartments through Booking.com or Airbnb, rather than use hotels. This option may give you more flexibility.