I've played to the end of Grandma's House 5. I tried to load the saves to Grandma's House 6 and it shows successful import but they don't show in the saves. It's been a problem that hasn't been corrected and I'd really like to play on.
Thanks for reporting this! Unfortunately, save transfers between different versions may not always work correctly. Hopefully, this issue will be fixed in a future update so you can continue your progress.