Students Migrating Home for Christmas?

I am not very optimistic about the smooth functioning of the postulated arrangements for a 'safe' return home for UK University students, in time for Christmas. The main problem (as, was the case when they went 'up', at the start of the academic term) is that student migration involves thousands of social, young people being dispersed to all corners of the country. Most students will be relatively unaffected, if they have a Covid-19 infection and some may be asymptomatic. The 'plan' is that students will be allowed to leave their campuses, in a staggered fashion, over several days (but I'm not certain how University authorities can actually stop someone leaving on the 'wrong' day, if it doesn't suit them). Students are being encouraged to have a Covid-19 test, before leaving but a) the available tests are not entirely accurate; b) some Universities are claiming that they don't have the capacity for testing on campus and c) students cannot be compelled to have the test. Students who test positive are supposed to self-isolate in their university accommodation, for the appropriate number of days, before leaving. That, again, will be difficult to enforce (one also has to ask what steps have been taken to help students do this?). Some students will be using public transport or sharing vehicles on their homeward leg, perhaps facilitating viral transmission. Some students might well be going to family homes, with mature parents or even grandparents. Older people are at greater risk, if infected by the virus. This is not to mention, relatives and friends, who might have underlying medical conditions (which are further risk factors for a serious infection). I'm sure that the vast majority of students will try to do the right thing but there does seem bags of scope in the exercise, for spreading the virus even more widely. I'm crossing my fingers! There are certain things I don't want for Christmas this year.