Li Shenron
Legend
How do people, generally, handle HP restoration in traditional DnD games? Do you buy lots of potions? Buy your healing afterwards from an NPC? What is the most common mechanic from the supporters of the dogmatic 'zero to nil passive HP regen'/'healing surges are bad' crowd? Do people behind this ideology always run with a heal bot? How do you heal 75% health on 4+ PCs without things getting out of hand?
I mean, even if you go light healing (say one cure spell per party), you're still looking at multiple days to get everyone topped off after a tough dungeon day.
I've heard a lot of decent on the matter, but very little in the way of alternative game mechanics? I really like the idea of this hardcore/realistic, but can't figure out a solution beyond "ok we're taking a week off so the healer can reset his/her CLW 7 times."
You've answered your own question: resting for as long as it takes is a solution.
If the party has a cleric or druid, it will require very little time, most often just one day of rest, since you can assume that all spell slots will be used for healing.
If the party has no cleric or other healer, it definitely takes longer but not an enourmous amount of time: in 3ed the slowest rate of natural healing is 1 hp/level, which means that a PC that has e.g. ~10 HP per level (probably a Fighter-type) heals about 10% of HP per day. Thus in the worst case of no healing resources other than natural healing AND some of the tough PC in the party are near-zero HP, it might take 10 days to heal completely.
In 3ed someone with the Heal skill can increase the natural healing ratio of everyone (except herself) to 3 times that, so you end up with 3-4 days unless she also was close to zero HP.
It's a problem only if you like all your adventures to be fast-paced with exhausting combats every single day and no downtime, in which case you should definitely change how healing works in your campaign.
For me these rules are not a problem, they are an opportunity for more planning, more varied strategy (i.e. not just rushing into every single combat but also consider avoidance) and even more creativity (because when you cannot fight for a day you can come up with some ideas on minor but still useful things to advance the story).