Joined: Jul 2007
Posts: 8,603
Likes: 3,532
From: South shore, L.I., NY
Bikes: Trek Emonda SL7, Cannondale Topstone, Miyata City Liner, Specialized Chisel, Specialized Epic Evo
It seems like you want a GPS that is only going to indicate current position, so as to verify on the paper maps, where you think you are, determine distance to a stopping point, etc...
As opposed to using a dedicated GPS that has routing capabilities. Garmin and Wahoo (as well as others) will do routing, but that begs the question as to how to develop routes a 1-1/2 year or so in the future, that allows flexibility. I don't see you generating in advance the ENTIRE route for 24 months, much less downloading that to a device.
Both a Wahoo (RideWithGPS) as well as Garmin (Connect) can generate routes and the easiest way to do this is on a computer by accessing the websites. This could easily be done on a tablet that also has web access. That would then allow a smartphone or tablet that has web access, to dump the route to the device via BlueTooth.
Just some thoughts.