Static Routing between two netgear routers

Hi,

The Orbi is connected to a VDSL (UK fibre protocol) modem.

The router is attached to some equipment that does have to travel around some times and needs to still be able to handle wireless connections and DHCP when it does (no internet connection required when it's travelling). If there isn't an easy option i may just turn on the DHCP when needed and leave it as a dumb switch the rest of the time.

I don't have a cable modem in the UK as the majority of us the internet is transmitted down a landline so no worries about IP conflicts.

Regarding the route there is a ethernet cable from the orbi's ethernet port (not directly) to the WAN port of the Router, the routers WAN port is set statically to 192.168.100.250 and that's what the route is pointed at. i have attached a screenshot of the static route config aswell in case I've just messed that up

Thanks in advance