You can, as long as the inverter already has firmware 428 or later. Also make sure you have the latest version of VEConfigure tools installed (because the update procedure downloads a before+after compound version which then has to be merged into a new settings file for upload, and only the latest VEConfigure understands that).
If you are worried, just do a remote Ve.Configure download first so you have the latest settings.
Also, although the system is designed to survive an internet outage, it goes a little smoother if the internet connection stays up during the update. So if your multi powers the internet… maybe move the internet to the grid for the duration of the update. Not absolutely required, but makes it smoother.