I would still floss as often as I do now, which is about twice a week.
I don’t feel any benefit from flossing and it makes no difference to my breath or appearance. Those are not the reasons I’d floss.
I would still floss because doctors are sometimes wrong. What if six months actually turns into a year, or a decade? Or if there’s an experimental drug trial that cures the disease for good? For me, continuing to floss would be my statement to myself and the world that I’m not resigned to just six months, no matter what the experts say.
Not only wouldn’t I floss, there would be a lot of other things I would let go. I would eat (if I could) whatever and however much I wanted. I remember my brother with a fatal brain tumor spending an hour on a treadmill two months before he died. Not for me. Back when I had stopped smoking, I used to daydream that I had 6 months to live and I could start smoking again. After about ten years, that daydream went away. Now the thought is revolting.
I would continue to floss to get the popcorn kernels unstuck because my diet would consist of buttered popcorn and candy bars and cookies. And I’d start smoking again but that’s another thread.
I personally wouldn’t unless i couldn’t like the feeling of tarter on my teeth, but I took care of a Sister who had a short time to live and until she could no longer floss she did.