I used to do multi-day rides of hundreds of miles all around Illinois and Wisconsin unsupported using just a map and some wanderlust. And I was taking offroad trails too in addition to unimproved back-country roads that sometimes didn't show up on maps. It's not really all that bad. It's a bit refreshing to just go out and say, "let's see where the day takes me". One just has to remember to take along enough things to be prepared for all forseeable situations.