First, I have to say that I don't know anything about being a resident somewhere else and getting a FL ID card. I don't understand why they'd let a non-resident get one, but I don't know much about it. I noticed you're from Canada, though, and here's what I found about Canadians:
Canadian Citizens
Under federal law, Canadian citizens are non-immigrants and are allowed to stay in the U.S. without obtaining INS documentation. Canadians without INS documents must provide proof of Canadian citizenship to be issued a Florida driver license or identification card by presenting two of the following documents:
Canadian passport
Canadian driver license
Original or certified Canadian birth certificate
Canadian Naturalization Certificate
All Canadian citizens will be issued an original or renewal driver license for two calendar years from the date of issue.
Here's the link
http://www.hsmv.state.fl.us/ddl/faqkeys.html#OOS
It seems like you'd need some sort of FL address as your own to be your address on the card, but maybe a utility bill from your in-laws' condo would do. Is your last name the same as theirs?
Now, for the FL resident passes. The FL seasonal pass is cheaper than the annual pass but doesn't give you all year - there are black-out dates at busy (holiday) times. The FL annual pass is cheaper than a non-resident pass. Either of these FL passes will qualify you for AP rates. Also, since your husband has a FL driver's license, you should be able to get FL resident discounts on the room, which are often the same as AP rates (and are sometimes offered even when AP rates are not offered).