To answer the OP's original questions - my kids are doing blended learning. We have 2000 students in our school system. So far we've had 1 positive case, and 15 students have had to isolate.
We're in a US state that gives all students and teachers a laptop or similar device. They also have a Apple TV in each room so they can project the laptop onto a screen. Technology is vital to make blended learning work.
Some students choose to be all-online.
Half the remaining students are in school Mon and Thurs. The other half are in Tues and Fri. No one is in Wed - this is when the school is deep cleaned.
This means less than half of students are in a classroom at any one time. Everyone wears a mask, and they stay 3 feet apart.
At lunch they sit 6 feet apart then can remove masks to eat. They can also remove masks if they're outside.
Students at home attend the same classes as those in school via their laptops using Google Meet. Attendance is taken at the beginning of each class. Homework is submitted online and marked.
Some teachers work from home because they are vulnerable - in those cases their classes are managed by a TA, and the teacher's laptop/webcam is projected via the laptop.
They've been doing this since early Sept and it is hard work but going OK.
The expectation is that everyone will take exams as usual when they are due.
They all also did online school from about 4 days after lockdown started until the summer holiday, so learning from home is pretty second nature to them.
For those who have younger children with two working parents, they've done things like set up childcare pods with other families, use wraparound care, get family help, take leave of absence from work, work from home, etc.
It's not as good as being able to go to school as normal, but it's helped us keep our infection rates very low, which means that life in general can go on - doctors, dentist, opticians, hairdressers, restaurants, shops etc are all open.
The goal of our state is to keep infection rates low and managed, rather than eliminate Covid altogether.