Well ahoy there, Pamela and welcome to planDisney!
That is an excellent question, and I'm glad that I'm answering it for you as I had a similar experience over the years as I sailed
Alaskan itineraries out on the West Coast. Now while we never want to have to end any cruise early, life does happen sometimes and from time to time there are folks who need to cut their voyage short to make it home for a myriad of good reasons. In my case, I had a family situation that forced me to make my way home immediately; my experience took a few hoops to jump through to accomplish, yet was not impossible.
Disembarking permanently from any ship is not an easy process and may require a lot of patience if you choose to make that decision.
One of the things that most Disney Cruise Line guests often do not consider when embarking on their journey are laws and regulations that govern travel by sea, which include the
Passenger Vessel Services Act. I recommend taking some time to read up on it online, but in short as it applies to your situation you may find it challenging to permanently disembark in Alaska if you were to begin your cruise in an American port. Luckily however, cruises on board the
Disney Wonder tend to begin and end in
Vancouver, British Columbia which thankfully avoids this and any fines levied against the ship by U.S. Customs and Border Protection!
I found that the best Port to head home from with the most options to explore in a shorter amount of time was the state capital,
Juneau; it was a quick ride to Juneau International Airport (JNU) that took less than 20 minutes. As a secondary option,
Ketchikan and
Sitka also have smaller airports with limited flight options. I would caution against the more northerly Port of
Skagway, as the few folks I've known to leave the ship permanently from there have had to take a combination of seaplanes and overland vehicle routes in order to reach any airports to take them further onward.
I highly recommend speaking with
Guest Services Crew Members and connect with the Guest Service Manager on board to them know in advance as soon as you board if there is any chance of you having to debark early during the voyage, as there will likely need to be a number of logistics involved to make that happen; the more advance notice they have, the more likely that this can be arranged. Be aware though that itineraries and any onboard passenger movements are subject to change and can never be guaranteed, so it's always best to be as prepared and patient as possible. (In my situation, I had to debark with just a few hours of advance notice and jumped at the opportunity as soon as I could!)
I hope that this helps you somehow Pamela; ultimately you'll know for yourself what your best course of action may be if you anticipate a possible emergency and need to postpone for another time in the future!
Please come back to planDisney again for more tips, tricks and insight before you set sail!
Wishing you all the best on your upcoming Alaskan adventures!
Prince