So, the middle son was getting married in the Ukraine because the girl is from there. That's all blown out of the water now. We've been quite lucky because we went through justfly.com and the first leg to Paris was cancelled. I just followed their instructions and everything was cancelled in two minutes, with a full refund on the credit card.
Not so lucky are the other people. They can only cancel a flight by phone, and nobody is answering. They are going to have to use the 'credit charge back' method if they can. The more direct flights to Poland and Ukraine aren't being cancelled. Ukraine is now 'open' to tourists provided they rot for 2 weeks in quarantine. Blah.