I previously speculated:

It would be entirely plausible to me if the number of foreign students in the next 25 years averaged half the recent peak, say. And not because of any potential Reform policy, simply because Chinese and other students will see better value elsewhere, and see that degrees from outside Oxbridge aren't guarantees of riches.
That isn't a forecast, but it wouldn't shock me..

Just for fun, and for a sense of scale, I wondered what the numbers would be on that plucked-from-thin-air scenario.

This academic year, non-UK students are already down about 15% from their peak in 2022/23 of 758870, so 50% drop from peak would be a drop of 41% from current numbers. (as an aside, EU students now make a pretty negligible percent of the total UK university student population, under 3%).
I believe non-UK students are still about 28% of Unite clients, so a 40% drop in that would be a drop of 11% in the total client set, other things being equal. Which they wouldn't be, of course. Presumably some of those vacated beds would be taken up by UK students instead, at least in the places with the highest demand, though perhaps at a lower average clearing price.

So, again unreasonably assuming no secondary effects or replacements, vacancy rates would rise by 11% on average if non-UK student population fell by half from its peak and Unite's impact was proportional.

It's hard to say what the impact of that would be on Unite. I suspect it would leave them lossmaking until a major retrenchment/restructuring was undertaken, with very unpleasant consequences for shareholders, but would not wipe out the company itself.

Jim