External ip-addres with DHCP

[AriePiet]

We have a 3200 appliance running Gaia R81.20

The WAN side gets an ip-address over DHCP and we manage this system with smartconsole.
For the moment everything is working properly.

What happens if the external ip-address changes because of whatever reason?
From my experience you always have to update the setting in Smartconsole, thus; get interfaces and then afterwards do a policy install.
But this means that for some time (until the policy is installed) you have downtime.

Is there a way to keep the firewall and internet connection up and running, without a new policy install?

I don't want to discuss the reason why DHCP is used here, nor do we need tips about keep in mind portforwarding/natting etc..

[AmirArama]

If the ip used to connect by the mgmt to the gw is dynamic. For that there is DAIP GW configuration when you select dynamic address checkbox. And dynamic ip on the interface in the gw object. However there are limitations with daip object as you can learn about in the daip sk's