I would say that you will have to pay for the scheduled flights booked by Celebrity on your behalf then clain on your insurance. I've not had personal experience of this (thank goodness) but seem to remember reading it in the terms and condition.
I am sorry to hear of your predicament but my suggestion would be to take the bull by the horns and ring Celebrity (0800 018 2525). They're a great bunch and will tell you what the situation is as far as they are concerned and if you make an anonymous call to the people with whom you have your insurance and ask them for a hypothetical answer they should advise you although do be careful with this one as it is surprising what they can construe from what we would consider a general conversation (one would assume that you have declared your husband's previous record when you took out the insurance). It may seem that I am being a bit gloomy but I hope that you are able to go. Also if you look in the brochure you will find out when the dates change for the amount of compensation they will expect either from you or the insurance company. Good Luck Neil Dow.
It all depends on how long it is before sailing - more than 57 days you should lose your deposit - the problem comes if the airline has already ticketed you for the flights - and you will then have to pay their penalty as well. As Neil says - call X and ask.