I think it wouldn't hurt to contact the hotel with your plans for 30 days and see if they can negotiate something in advance? For that price I'd just pay the corporate rate and keep the points for future stays at more expensive properties.

This property is nicer than some of the ICs that I've stayed in and is quite spacious. Wouldn't your family want a bit of a scenery change though? Staying at different properties in different parts of HK might make it more interesting. Taxis are quite cheap in HK that moving hotels aren't that painful.