We do not get insurance when we go to Disney. I have heard of situations where they let you rebook your trip and you do not lose money--excellent customer service philosophy.
We do get insurance from Travelguard when we cruise. We started when my dad had several recurrences of cancer. We did cancel once 2 days prior and got a full refund. They sent us several forms which his doctor filled out stating he suggested we not cruise.
Once I got a jury duty notice and did get out but it would have covered us if I couldn't. There is also coverage for job reasons.
We get it when we cruise because of the medical coverage you lose when you leave the US. Our son is diabetic so we pay within 14 days of deposit to get prexisting condition waived.
You can pay extra to get cancel for any reason but your refund is only half of your cost. For our cruise the policy is $115 and to add cancel for any reason was $43. We did not feel it worth it to only get half our cruise back.
Travel Guard has a few plans. We get the gold which is the middle priced plan. If you have kids under 18, one is free for each adult on the gold but not the silver.
For your cruise portion, do not figure port charges as part of your trip cost. If you cancel, the line will refund them.
Every so often I compare companies on insuremytrip and TravelGuard is always the best coverage for the price.
If you are past the 14 days since deposit, I would wait until you make final payment to get insurance. Travel guard allows this and your coverage will be the same other than preexisting coverage. That way if you cancel the cruise or change sailings, you have not wasted the insurance. I have not sailed Disney but the lines I have allow you to cancel up to 76 days prior with a full refund of deposits. Longer cruises (15+ nights and holiday sailings) have earlier cancellation dates. A
travel agent might charge a fee for cancelling.