I mean, propper cycle gps/satnav is bloody expensive...
...Could you not just use a normal TomTom if you're just riding on normal roads?
I know there'd be a battery life issue but say for example, you're off out on a long trip along unknown roads and get yourself lost. Rather than faff about with maps, could you not just have an old tomtom one in your luggage/saddle bag and fire it up for a bit while you get yourself sorted out?
I want to ride around Paris using my TomTom for street mapping , anyone got a view using a battery in the saddle bag, how big should it be for a days ride