Crowne Plaza would probably be your best bet, or there is accommodation at the Sebel itself. If you can find out numbers of how many are planning on staying up there, you might be able to get a group booking discount maybe

You will also need to consider travel to and from the Sebel. My SIL got married there and they organised a bus for everyone, but taxis etc aren't generally around there and could be expensive

If all else fails, we live half hour drive and have a spare room