First of all, I haven't committed to booking EZAir flights. As always, it will depend on pricing and scheduling. However, we have in the past found EZAir international pricing to be very competitive so I will certainly be investigating once the flights become available.
Second, although anything can happen your scenario is so unlikely in my view that it will not be part of my decision making process. However, I must admit I hadn't thought of this potential eventuality.
Finally, I would most likely still take the land tour. It is very immersive and we are very much looking forward to it, perhaps even more than the cruise this time around. We might even add additional touring before or after the currently booked tour in place of the cruise.