As far as I know, our school found out via the same press release that we did, that schools were going to be closed.
So, not a shit load of time to prepare to go to a completely novel way of attempting to educate children with extremely variable resources at both ends of the equation - the school and teachers' end, and the family end.
Keep in mind, also, that many teachers are also parents, who are equally stressed and worried about their childrens' education, trying to juggle that with working fulltime teaching other peoples' children, and attempting to also do pastoral care with children they know are at risk and vulnerable at home.
My girls' first school was proudly mediocre. It would move Heaven and Earth for those who were failing, but were quite vicious in their refusal to perform any sort of extension (even to the point of refusing to use a higher level reading book) for the children that needed extension. Especially if they weren't the proud possessor of a penis.
One thing that taught me was that sometimes it's down to me to ensure that my kids got the education they deserved, you cannot rely on the school or teacher to either want to deliver or be able to deliver the education experience they need.
(That is no reflection on any teachers in here, or any school but the one I'm talking about - I ended up on the Board of Governors (equivalent) of that school, and got to know very well why the school had the challenges and attitude it did.)