We are using the NetGear Nighthawk R6700 router flashed with DD-WRT firmware (build r42617).

Note Make sure you erase nvram using nvram erase and then reboot right after you install the firmware or it will crash. Also make sure you use the .chk version for the first flash from factory.

Used these docs to setup the 5ghz antenna to be a client to other APs to get internet access (i.e. from house):

[https://wiki.dd-wrt.com/wiki/index.php/Client_Mode]

Important Note When you setup up the IP address range for the router be careful not to collide with the destination's IP address range. For example don't use 192.168.2.0/24 if your home network is 192.168.0.0/16. I picked 10.2.1.0/24 as my range but there are lots of options. Also keep in mind various in the wild APs may also be using something in the 10.0.0.0 range. Here is a list of Private network and otherwise reserved IP addresses.

You will need to make sure the router (specifically the MAC of the 5ghz antenna) is assigned a static IP by your home DHCP server. Then you can add a route for traffic wanting to go to 10.2.1.0/24 to map to that IP address.