For my back-of-beyond tours, I take
two GPS units and the same maps loaded on my phone(s) with various apps, but try very hard not to use the phones because they are my primary source of communication. Electronics do fail...my Garmin Oregon 400T rubber power button split, then perished entirely on my on my return leg through Romania and I had to cover the hole with a plaster for continued waterproofness and turn it on and off with sharp sticks found roadside. Paper maps and a compass are always with me as well, for backup.
If you'll be staying in lodging regularly, you may consider asking your hosts to draw you some crude maps with the roads labeled. I've done this on occasion with restaurant or hotel staff and found them remarkably accurate compared to my GPS maps/tracks and also sprinkled with "special features" like favorite picnic spots and family swimming holes...even restaurants and lodgings operated by relatives at a discount for "friends and family". I found a delightful pension in Romania that way...and a
cafe rustica operated by a cousin of the proprietor...and one of the best roast ducks I've ever eaten, at a discount! The fresh vegetables were gathered from the garden out back while the duck was cooking and I petted the family cat while catching up on email. I never would have found the place on my own.
If you will be relying on a phone app, be sure you can access your maps while offline. Nearly all apps allow this provided you download a base map in advance, but sometimes you can find yourself riding past the tiles you've downloaded and will then have need to do some updates using wifi provided along the way.
I like riding with cue sheets , usually made fresh the night before or morning of my day's ride, but there's no reason why they couldn't be made well in advance; I sometimes do and it has worked fine. A mainstay of randonneur riding, it allows me to concentrate more on the ride and scenery and to use my maps to resolve any routing questions, typically at turns. Explained a bit more here...
http://thorncyclesforum.co.uk/index.php?topic=12866.msg111046#msg111046Enjoy your trip!
Dan.