Groton did a better job with covid than Milton. Hands down and by miles. The Groton administration is top notch and the Milton administration is not. Complaints about the Milton administration abound the academic groups I’m familiar with.
I wouldn’t worry about getting covid at school - even with a roommate.
The workload is high at both. If you are super worried about too much work neither school is appropriate for you. But. If you aren’t doing outside of school activities it is manageable. I have come to see, after two kids at top schools, that outside activities are what sink you. I don’t think my kids would be stressed beyond the “normal” for highschool without that extra time commitment.
You will get an excellent education at both schools.
Groton’s 3/4 walls are special and make it more family style almost. I don’t know any kids at the school that really dislike it and it’s only for 9th grade.
Ask to speak to students at each - and take your time. You have until April. Use it.