Changing Apple Store country without affecting family iCloud account

Apple is pretty clear about this not being supported. There are no practical solutions.

Legal - Apple Media Services - Apple

"All Family members must share the same Home Country."

Share purchases with others in your Family Sharing group

Share purchases with others in your Family Sharing group on Mac - Apple Support

"To share purchases, family members must be in the same iTunes Store country or region."

Check this link here for more details: Change Purchase Sharing settings in Family Sharing on Mac --> Change Purchase Sharing settings in Family Sharing on Mac - Apple Support

- "Note: To share purchases, family members must be in the same Apple ID country or region. If a family member changes their Apple ID country or region, that person might lose access to other family members’ purchases, and installed apps that were shared from other family members might not work. See the Apple Support article Change your Apple Account country or region - Apple Support ."

I am afraid this is not possible. For family sharing to work, you all need to be in the same region with your apple accounts