Hi @winterrabbit, we have a trip booked in late January. Our 14yo is single vaccinated, but can't have his second vaccine until late Feb. So we are in a similar position.
Our accommodation won't discuss a refund or credit until the day before our booking so we are waiting with baited breath. They also do seem to think that our son's vaccine status is our own fault so may not apply the refund rules that we thought were relevant.
The big 'if' atm is whether the travel ban will be lifted. Lots of people think that maybe it will be lifted because France's infection levels of Omnicron are so high that keeping us away seems futile. But who knows?!
I believe that the French Pass Sanitere may change to a Pass Vacinere on 15 January (subject to red tape). This is the pass for French citizens and it sounds like it will mean that they can no longer get a pass using testing- so their only option for a pass is to be fully vaccinated.
As I say, this is for their own citizens atm. However, I can't help thinking that they will insist on something similar for travellers, but as yet I can't find anything remotely official about it.
Finally though, if your DS is exempt from vaccination for health reasons it may be that other rules apply.
So keep me posted if you find out anything helpful. It is worth being cautious with google though- as so many pages are out of date....