Monday Hour One during pandemic with children at home

Hi, everybody! I struggle with my time management. Before the pandemic, I was rocking the Monday Hour One system. My children were in daycare, and I was good at doing my tasks.

At the moment, I try to make a plan ahead, but I find it difficult to keep up with it. Often my children, 2 and 4 years, have to stay at home unexpectedly (daycare closed or they are not allowed to come because of a cough.) Although I tried to get my lower tasks done, I see that I cannot work as concentrated with the children around me as I can alone.

How can I plan my week ahead when I don’t know when and how long my working hours, leisure time, etc will be?

I already tried to just stick to some tasks instead of time slots (e.g. “Write 500 words this week”, which I normally do in half an hour.) Even if I lower my weekly goals, I can’t keep up with them (all of my buffering time is not enough). On the other hand, I really want to do the tasks because I want to keep my deadlines (I’m a writer).
My husband helps a lot with the children, but he works as well and his boss does not allow him to be at home for child caring.

Any suggestions?