If you're booking on Expedia, you can specify that there is just one in your party when you do the original search. If you go ahead with your booking, it will only be for the one as you have already specified. You can still choose the room you want like normal. Having said that, I don't believe that there are any 'twin share' rooms at HKDL, at either hotel. As far as I know they all have either 2 queens or a king.
FWIW when we stayed at the DL Hotel we found the customer service was great, and they were more than happy to move us when we weren't happy. I had forgotten that I needed to specify non-smoking, and the first room smelt awful!. 10 minutes later we were in our lovely new room with a balcony for lots of nice fresh air. We also had a great experience at the Hollywood, had our request for a high floor honoured, and also got some lovely anniversary pixie dust