Well...
Laptop is your friend. A cheap one just for controlling your CNC machine.
Buy a decent external controller, not cheap chinese, but one that connects with your computer over LAN cable, eg. USB SmoothStepper, Pokeys57, Purelogic PLCM, ...
Walk 80m to your workshop with laptop, connect LAN cable and off you go.
When you finish, unplug LAN cable and walk back 80m with your laptop.