The Garmin Connect routing maps have bike paths, if you are using the web to create, but with WiFi or cell data you can do that from a phone or tablet
The Garmin 1000 pretty much does what you need, only downside is the battery is 10 hrs in navigation mode. You then need either a recharge stick or brick, or solar. The unit can run while being charged. the 1000 used to sell for $500 and is down below $300 currently.
Wahoo Elemnt as well, very reliable, maybe 12 hrs battery while navigating, some philosophical differences in design such as buttons to control vs. touch screen on 1000, B&W but very readable screen (except in turn-by-turn) on Wahoo, va. color on Garmin.
Not cheap units but they do a bunch of things well, are waterproof, easy to read in sunlight, etc....
I knew a guy that used his iPhone to get across the country, he used a solar panel to keep charged. Seemed to work for him.
Last edited by Steve B.; 03-04-18 at 09:02 AM.