Hi Charlie,
You can't do it wirelessly with the current Navbox hardware, using a single laptop.
Although you could possibly do it with a 2nd PC downstairs using 'Logmein' over a wireless network. Logmein has a free version, and simple to setup. You could then keep your laptop switched on 24x7, and just login remotely. Its quite effective.
Alternatively, if money is no object, the easiest option (in my opinion) is to subscribe to the Airnav 'Live' network for distant flights, and just pick up the local flights with your radarbox antenna in a nearby window. Signal strength is then not really important.
Hey...Why use a laptop for Radarbox when youre at home ?
I have a relatively cheap Nvidia GTX260 graphics card on a desktop PC, with dual monitor output, and 'spread' the Radarbox display across 2x Samsung 24 inch monitors. Its incredible, especially when rotating the 3D display. Once you've experienced the 'Imax' panoramic effect in 3D there is no going back to laptops. ;-)
Also I like to run Planeplotter (with MLAT) alongside the Airnav Interface, to view Flybe flights at my local Exeter airport. (as they dont use ADSB). So dual monitor is the only way to go....so no laptop for me anymore...as I cant stand squinting, and eye strain.
Just my 2 cents worth anyway ;-)