I find your statements in different parts of the thread quite contradictory. On one hand you say that things don't scale because of number of students, but then a bit down thread you mention it's not worth making a new course for 10 students (out of 640), but for 10 students in person proctoring is clearly not a problem.
You also mention the issue of cheating for professional qualifications, but again, that's a tiny fraction of all exams.
Regarding scaling of oral exams, there's actually some interesting research/calculations (I try to find the reference later) and the cross-over is somewhere around 150 students when oral exams become slower (I do think this is quite teacher and subject dependent though).
Also about budgets, I believe that your department is spending more than ever, the issue is property services departments of the universities should be saving large amounts. Considering lock-downs and staff and students working from home, maintenance cost should be way down. I suspect though that money lands in completely different buckets (don't get me started on the business of university property services, we pay rent in our overhead cost when we get grants that are higher than renting office space on the main shopping street in our city).