i've been thinking about doing the same thing for some time now to use as a cold storage. i think i am gonna do it now that i read this

and as far as i know uploading "Encrypted" wallet backup to google drive can be safe and you can change the name and type of the file too, like changing it to "crocodile.webm"

How do you change the .wallet ending without fucking up the file?
He just means renaming it to something else (file name and extension), without changing the content in any way. If you then need to use it again, just give it the original name and extension first, and you should be fine.