"And anyway, your figures show that the majority of Oxbridge/Russell Group students don't come from private schools"
So what? The contention was that there were very few students who could afford luxurious living. I'm merely pointing out that it's more than "very few".
"What about non-Oxbridge/RG students? I'm betting that an even smaller proportion are from private schools."
Obviously. But residential university life, as opposed to people living at home, is still heavily dominated by the middle classes.
People starting university now were born in 1992. The middle class parents are probably now in their late 40s, having either gone to university in about 1980--83 or got a job in about 1980. A significant number of them will have paid their mortgages off. All of them who bought houses in the 1980s (care to guess at rates of parents in rented housing amongst full-time students going at 18? I'll bet it's lower than the population at large) will be sat on huge positive equity. A non-zero number will have all four grandparents having died, and the parents of people going to university now are the people getting huge capital injections from the equity growth of their parents' houses.
Sure, there's student poverty. But there are a lot of students who are living very comfortably.