I can give you a Eurocontrol validated airways route e.g.
EGSR CLN M189 DVR L9 KONAN L607 GELPA/N0148F120 L607 RUDUS/N0155F100 L984 OKL M748 DEGET/N0133F170 M748 ARPOS/N0155F100 W85 DVA T2 UREKI/N0151F110 L851 DIPIN M977 BEDRI LRBS
1170nm
but you will have a job flying it with a C172 without a ferry tank
Also somebody will need to do some serious donkeywork to see where you can go without Mode S.
Perhaps you meant VFR? That will involve looking through a load of VFR charts, plus a lot of donkeywork around the national AIPs. It's easier to fit Mode S.