So many factors will play a role in determining whether schools will reopen and the number of pupils they'll be able to accept at the start. You may choose to keep them off but it might well end up that you can't choose to send them in either, as legally the school might not be able to keep them safe.
I am a teacher, I am in the vulnerable category. I have colleagues who are also extremely vulnerable and others who are living with people in both categories. Our Head has been so supportive and has kept us all off the childcare provision rota and working from home for these reasons and on local authority advice. Those staff in good health/not vulnerable and not living with vulnerable people makes up 46% of the whole staff team.
My school does not currently employ a cleaner, either as they retired just before lockdown and school hasn't been able to recruit a replacement (would you send your children in, knowing this?).
My classroom has only enough chairs and tables to seat 24 out of 30 children within the room (so we already spill into the corridor and wider school environment for working space) regardless of lockdown. This would make social distancing completely impossible unless class size was significantly reduced. The rest of the school is the same. Our outdoor space is very, very limited as an inner city school too, so that isn't an option either.
As much as parents may well like to send their children back in to schools as soon as they potentially reopen, the decision may well be out of your hands.