One of my colleague Goldsters out of Newcastle had a very similar problem when his company's ownership changed. He simply decided that flying Y is not what he did and resisted all blandishments to fly further than Paris. Eventually his boss pleaded with him to get a doctor's certificate, but his logic was "why should I? I am 58 years old, I don't actually like flying and all C does is make it tolerable". Eventually management capitulated and exceptions were made in his case.

A lot of corporate travel policy hinges around the perceived "pleasure" of flying and/or the acceptability of Y travel. This may work if you're 22 and eager to see the world. If that frankly doesn't work for you or your OH, just say no.