It is certainly a complicated subject but you should be able to pull it off following the guidelines that are available from the Government.
You can keep your house as an investment property as long as you take steps to establish its current market value and rent it at "arms length"
The biggest criteria seems to be what your wife and kids do. If you pack up and all move to Hong Kong, everything will likely work out. If they want to stay behind, it will be much harder to meet the tests established by the Government.
For more information, you can see Interpretation Bulletin IT-221, Determination of an Individual’s Residence Status
You can also call the International Tax Services Office at 1-800-267-5177 to chat about your options.