Me and my husband are planning to travel to hongkong for 4 nights.

We plan to stay in a hotel in mong kok or tsim sha tsui. basically, go to disneyland,ocean park and even a day in macau using ferry.shopping, go to lantau islands as well. i do have my octopus card way back 2012. when i moved to canada.3 years ago. i dont know if my octopus card is still working. will it still work? if so,how much should i refill that for that to last in my 4 days? will it be cheaper for me if i buy my husband an octopus card for 4 days going to all these places or just buy the one day pass everyday for 4 days? hope to hear from you