In the early 70's my School closed down due to the Miners strike (no fuel for the heating boiler), we had 7 weeks off, it was early new year so similar to now. We played football every day, found things to do and lived every moment of our "free" holidays. When we were told the school was reopening me and my mates were gutted, so much so, we cracked on we hadn't heard the news and only went back once a letter arrived at our parents houses.
Different times but I don't buy into the mental health problem for most of the kids. Send them back in March and let them have a shorter summer break in August.