Catch Some Z's.
4e's current resting rules are remarkably elegant, but they carry a bit of a problem.
Namely, it doesn't make a whole lot of sense that I can be bleeding from seven sword wounds one moment (down to 2 hp!), and then suddenly fine in five minutes (surged to full!). It also doesn't make sense that I can be nearly at my rope's end before I go to sleep (down to 1 surge!), and then peachy keen the moment I wake up again (full up!).
However, the idea of short rests and extended rests — and the markers that they serve as — are very valuable methods of pacing and resource management.
How Short Is Short?
So, a simple fix:
Short rests are overnight. Extended rests are a week.
All this does is change the timescale at which rests operate. It makes some sense that you'd have some of your strength back after a good night's sleep. It also makes some sense that after a "vacation" where you can mend broken bones and the like, you might be reasonably back to full health (as a heroic character in a setting with magical healing can be!).
Just the Beginning…
You can take this idea further. A short rest is a week and an extended rest is a month? A short rest is a month and an extended rest is a season? A short rest is a season, an extended rest a year? A short rest is a year, an extended rest five years?
Some of those longer scales might make more sense for dynastic-style games than for a character-focused game like D&D, but still, the possibility is there.
You don't need to change what the rest is capable of, you just need to change the speed at which it happens.
Bam. Now it makes a little more sense for you to be beaten and abused before you retreat.
What It Doesn't Fix
Surges. They are still employed in this model, though this model could reasonably be combined with a "surge-less" model, since the rest mechanics don't necessarily depend on surges to function. At any rate, here out the gate, the surge just gets spent at a different rate, Kate.