Opening both new and existing Calc Documents produces a small centrally located window of proportions that are always going to require resizing to permit anything larger than a 10 x 17 grid with the current default calc/grid characteristics.
If I'm not mistaken, just about every windows program in existence (probably since windows 1) remembers the coordinates, window size and content of the last utilisation and reopens the application/file accordingly. Under those circumstances I consider it to be a bug as opposed to an enhancement request. Would you disagree?
It's not a major issue if individual files don't immediately have the last used default but the current global default size is about as much use as an ashtray on a motorcycle - to anybody wishing to use a spreadsheet as a spreadsheet rather than perhaps a small picture frame.
A similar bug report has existed since 2012 but that was set to solved by somebody, late last year, who claimed to have fixed it in a UBUNTU LINUX environment. In all honesty, I couldn't find that solution in his posts for either Windows or Linux so I suspect it was (mistakenly?) flagged as solved.
1. The initial window should be defaulted to at least 80% of the available desktop (check the user's monitor size).
2. The user should be able to modify this initial default size in Calc settings.'
3. The application should update it's own parameters - or the Window's registry if appropriate - when a user (customer) manually resizes the window - in order that the last used status is restored.