Wilderness travel as outdoor survival

I don't like the traditional D&D hex crawl. I think my problem stems from the fact that I started with AD&D, and to this day I don't understand the point of AD&D's wilderness rules. D&D Vol III: Underworld and Wilderness Adventures has a simpler system, but makes a lot more sense. Dan from Delta's D&D has a great series of posts looking at Outdoor Survival, the game OD&D tells you to play instead when you're wilderness traveling: http://deltasdnd.blogspot.com/2016/09/rules-of-outdoor-survival-part-1.html

I'm experimenting with the idea to make Wilderness hex crawls more interesting by making them survival simulators. Instead of just wandering monsters, I could make chance of getting lost, diseased, or dying of starvation into possible factors. Starvation is a big point, players usually ask "What if I don't buy rations?" in D&D, and 5e solves this by adding an "exhaustion" mechanic, but I don't want to add even more rules to the game.

In previous games, I simply told players that nothing happens until they go 7 days without food or 3 days without water, and then their character dies. That seemed to be enough for players, and surprisingly they've all eaten every day instead of waiting for 6 days between meals. So far, nobody's abusing the system so I won't enforce a change, but in case someone decides to, I'll add an optional rule, that days without food increase your encumbrance value. I figure that mimics the "Life needs" system of Outdoor Survival close enough, without needing to hand out survival cards to every player.

The wilderness travel rules in AD&D and B/X/BECMI both abstract travel into periods of days. This is actually frustrating when playing B2 The Keep on the Borderlands, since it gives you a map divided into 100 yard squares. B2 gives movement rates in terms of squares per hour, and I'm not really sure that lines up with the daily movement rates or even the individual encumbrance movement rates. The "squares per hour" movement system also echoes back to Outdoor Survival's grid based play. Yet even for all that, I found B2's Adventures Outside the Keep to be pretty boring, taking place on a mostly empty map with only a handful of encounters, requiring the DM to invent material to keep it from being boring. And every time I've played B2, I've had to invent a ton of material to fill out the map.

That's the puzzle I'm trying to solve, and I think it will be an even bigger issue with a larger scale map. Maybe threatening players with starvation, disease, and unintended movement simply for journeying in the world might add an interesting minigame, or maybe it would bog them down in tedium.