The 'keepass.kdb' file needs a password to open it. So, if you're worried about your house burning down and you trust google, you could keep a copy of it in Google Drive. If someone hacked your email account, then they'd have to brute force it.
You could also keep a copy on a USB stick and leave it in the care of someone you trust (mom, dad, sister, brother, friend etc). Even if they tried to read your passwords they couldn't open it unless they brute forced it. I guess how far you wish to take security and safety precautions is entirely up to you.