On Priceline, you can ask for a room that will fit 4 or 5 people, however, it is NOT guaranteed. I still remember our family of 4 getting a room on Priceline in New York City. I called ahead to the Hilton Hotel and Towers in NYC to ensure we would get 2 doubles. But when we got there, the hotel was sold out and all we got was a 1 queen bed room for the 4 of us. They told us that it was a Priceline inventory room. After a bit of "discussion", they finally moved us 2 nights later.
Also, if you get some place like the Hyatt Orange County, either on Hotwire or Priceline, they only allow a max. of 4 in their standard rooms (which is what you get when you buy from Hotwire or Priceline). They don't allow rollaways to fit the 5th person due to fire code (I've been told that). So what one is usually forced to do is to upgrade (for $40 per night, I think) to a kidsuite. But if you get the Marriott, this hotel chain tends to allow a 5th person in their standard rooms.
Have you looked at the Marriott Anaheim Suites? I recently got a room there for our July trip for $99 per night on a AAA discount. It can sleep up to 6 and includes a mini fridge and a microwave on request.
