Cross Border Issue

I recently asked about making a suitable offer to my STBXW but a new complication has arisen. My father has told me he is terminally ill and he, along with my mother, are the carers to my disabled sister. Together they could realistically have continued for another decade whilst my children grew up but I now find myself in a situation where I am needed in two places. To add to the complexity, my family lives overseas albeit not so far away that visiting EOW would pose any difficulties.

The biggest issue is earnings. I know I cannot quit work to become a carer and would never do so anyway, I have to strike a balance to be responsible for all of my family. However, home is somewhere where housing costs are stratospheric but salaries are about 20% lower net than where I work.

Is there any case law considering the reasonableness of moving home when home is abroad and incomes are lower? On my current salary spousal maintenance is an issue but unlikely but child maintenance would be a bit lower and it would also render a Mesher Order (something I am opposed to anyway) unworkable because my STBXW would not be able to afford the mortgage.