Here’s one (but if a doubled-edged sword though, as with everything Brexitty).
At least for the next year or two, it should be much easier to get your DC into a uni (although take care to choose one that is less likely to collapse into administration). There will be fewer lecturers and their terms and conditions will be even more compromised than they are at the moment, but hey ho, you can’t have everything.
There should also be lots more uni-owned housing on offer for your DCs, as unis have invested heavily in their own accommodation blocks with lovely bathrooms etc, not anticipating flight of EU students.
The uni experience will be ‘British’ again, as it was in the 70s and 80s.
Also, more graduate opportunities maybe! (although eeek fewer jobs, so as with all brexit ‘advantages’, this one doesn’t bear too close scrutiny). In any event, moving swiftly on, there will be far fewer well educated and multilingual foreigners to compete with Leavers’ DC for job opportunities. This must be a ‘good thing’. It was certainly a key advantage highlighted on these threads before the referendum, as I recall.