Just to be clear, because I know I'll get posts about what a bad idea it would be to go otherwise: we are not going, we decided that a while ago, my question is about whether we cannot go, or are choosing not to.
We (DH, me, 2 year old DS) have flights booked (booked ages ago to head off the questions about why we were stupid enough to book them) for the week after next to my parents' holiday home, which is in another country - one with an air bridge to UK that doesn't require quarantine at either end (at the moment). My parents were supposed to be coming too, and have their own flights booked. We had already decided weeks ago that we wouldn't go and would just have to lose the cost of the flights. The airline does allow you to move them, but only to the end of March and that's no good to us because I'm pregnant and due in Feb, so we were just going to suck up the cost since my understanding is that this holiday would have been perfectly legal, just unadvisable, and so our choice not to go.
The area that both I and my parents live in has just gone into tier 2, so we cannot meet indoors. As far as I can see, though, we can still go abroad and under the rules of the country we would be going to we could legally stay in the same house - but not under UK rules. Does this mean we now cannot go? Again, we're not going either way, but I'm wondering if we now might have any hope with travel insurance (which we have) or the airline if we're in a situation where we can't go as opposed to choosing not to?