From the comments on this thread, it appears that GCT has improved their handling of trip cancellations necessitated by "natural disasters" and circumstances/events beyond GCT's control. This is a very welcome change.
In 2010 we were scheduled to depart on a Monday in mid-April for a GCT river cruise in France. Thursday prior to our scheduled departure date the volcano in Iceland erupted, bringing to a halt all air travel. We called GCT to ascertaiin what to anticipate and their resonse was twofold: 1) the trip (i.e. the ship) was departing on schedule and 2) we had to deal directly with the airlines -- it was not GCT's responsibility.
Well, the airline would only discuss possible flight changes with the "agency" that booked the flight and, therefore, would not speak with us. They would only deal with GCTG. At the same time, GCT held its position that ur flights, booked through GCT, were not their responsibility. While feeling caught between the proverbial rock and a hard place, proved to be academic since there was no way we could get to anyplace in Europe in time, this was a most disturbing state of affairs..
Through Sunday, the day prior to our scheduled departure, GCT maintained their position that the trip was not canceled and that the air arrangements were our responsibility.
Thankfully, we had our own trip insurance and did not purchase GCT's. Our insurance company advised us as to how to proceed and on Monday, the scheduled day of our outbound flight, we canceled the trip.
I must add, a few days later GCT phoned and offered to re-book us on the same river cruise at a later date with no change in price. We accepted the offer (canceled our insurance claim) and enjoyed another wonderful trip.