Angels have the Phone Box
Yes, you can login with local accounts, then setup OneDrive in each account, entering their MS login credentials. You may find that every once and a while MS will want them to verify their credentials, but it's no big deal. Either way, upgrade or clean install, (both take about the same amount of time, but the prep work for an upgrade takes a while), the system will get the activation and you won't be rushed to get programs installed if you do the clean install. You could throw a bare drive in, install clean and use the W7 key to activate it, then take your time installing all your programs.