I know you said you as a family had discussed it many times but basically it's either your current lifestyle and working 80 hours a week or downsizing ?
My perspective . I was in a similar situation only a year ago , earning big ( same job with another employer would be 40% max), working crazy hours , getting burned out. The sad irony of our situation was that big money wasn't saved , it went all on servicing debt from post GFC mess :( not consumer debt , just bad investments .
After 5 years I felt trapped , resentful, unhappy, unfit and my marriage suffered . In a strange twist , my workload reduced suddenly ( loss of large client by our team), my money dropped .
In December I started taking lunches every day, leaving on time , started yoga and other classes 4 times a week, started biking ... My life changed!!
Now I work less, earn less but rather have this work life balance . It was forced upon me but it was really a blessing . We just downsized to smaller cheaper place so our decision was to keep downscaling our expenses and stop working soon- ish than to have one of us ( or both) to burn out to the point that our health will suffer irreparably.