Upgrade firmware via 3G

Hello, I’ve a Balance20 with only a 3G dongle as WAN, connected via IPSEC vpn to the central site.
The Balance20 is running 5.4.9 , and we would like to upgrade to 6.1 and join it to incontrol2.

I have the 6.1 firmware key ready, but I’m concerned about the upgrade: once I upload remotely the firmware and reboot, will the Balance reconnect to Internet using the 3G and register to incontrol2?
Or I need someone on the LAN to manage it and paste the key?

I haven’t any IT on site, so in case of failure I need to have it shipped back to HQ…

thanks
G

Yes, it will connect to the Internet with 3G and register to IC2. After that, you can input the firmware key via Pepmin.