This Dragonlance adventure is pretty interesting - while it does have some railroady elements, it's actually a limited sandbox of an adventure.
The basic plot is that the PCs just finished DL2, and escaped from Pax Tharkas after freeing the prisoners of the Dragonlords. They end up on the far side of the fortress, encounter the refugees, and then have to guide them to temporary safety while they find a way into the Dwarven kingdom and long-term safety.
They need to evade a pursuing Dragonlord army which relentlessly spreads out to conquer the lands at a pre-determined pace.
It's set up nicely - there are both timeline and location based encounters. There is a tradeoff for humanity - you can ditch the wagons and the old and infirm for speed (if you can convince the refugee leaders to do so). It even suggests an XP value of 10 per refugee you get to safety, so "victory" is measured in live bodies and not just dead enemies. Lots of tradeoffs to make, the refugees don't automatically listen to you (they elect their own leaders who make you advisors), and you don't always know what's waiting for you.
There is a pretty cool dungeon in it, too.
I suppose people can find a way to make this a railroad ("But what if you don't want to escort the refugees?" Etc.) but it's pretty open. There is really only one good place worth ending up, for a variety of scripted reasons, but again, the idea is sound. Explore while fleeing. :)
DL3 Dragons of Hope
What can we salvage?
The Mass Combat System - a very quick-and-dirty mass combat system comes with this. Basically armed 1st level NPCs count as 1 point, PCs and name NPCs count for 5 each, and using magic, defensive position, terrain, etc. counts for more. Same for the bad guys. When you have an encounter, you make a roll to see if the shaky refugees even stand and fight. If they do, both sides roll to see what they do to the enemy.
It's not a bad system, and I think it could work outside of this context with a few tweaks - say, above-1st level folks are worth 1 pt per level, higher HD creatures the same, etc. and roll and inflict damage. It would be fast and bloody and determine casualties quickly.
The Political System - I like that the refugees immediately create their own council of leaders and relegate the PCs to lobbying for their decisions. There is a dice-based system for politicking, although the module does say you should roleplay it much of the time. No matter, it's the dice-based system that might work elsewhere. Why put the PCs in charge when they can be forced to dicker with NPCs and horsetrade to get them to do what they think is best? Sounds like fun.
The Attrition Rules - What if some of the refugees melt away, or die off? Covered. Could be useful for military attrition, too - something I rarely see come up in games. Easy steal to see how many orcs or mercs or hirelings are there each day as the PCs force march them around looking for trouble.
The Area Crawl - The refugee movement around the area is by hexes per hour, but encounters are by area and Dragonlord conquest is by area. This makes the PC-centric decisions tactical and narrow in focus but the referee based ones simple and broad. Nice. Plus the whole idea of "get the X to Y before Z arrives and wipes you out" is a good wilderness plot line. Change the Pax Tharkas refugees to the caravan of bickering merchants and the the safe zone to the oasis and Z to raiding bandits and you've got a desert adventure all ready to go. You can steal this whole idea and the tools above for dealing with mass group adventuring.
Skullcap - Another 3-d dungeon map, complete with a kickass descent (climbing down the shredded remnants of a destroyed metal staircase), a 3-level maze of invisible walls and floors guarded by an active mechanical defender, and a few trick rooms that make sense in context and in the game world but which are also challenging. Oh, and you go in the dungeon through the eyes or mouth of a skull-shaped rock, and they aren't all paved entrances. This one is a good whole-cloth theft target.
Draconians - the same three from the previous books are here: Baaz, Bozak, and Kapak. Nice pictures of them, too. Useful if you don't have earlier books.
This whole adventure, except one useless bit with Gully Dwarves, is worth ripping off for rules, locations, and a good method of using a wilderness hexcrawl with external pressure. The series might be flawed but this one has a lot of good stuff in it.
The Rest of the Series:
DL1 Dragons of Despair
DL2 Dragons of Flame
DL3 Dragons of Hope
DL4 Dragons of Desolation
DL6 Dragons of Ice
DL7 Dragons of Light
DL8 Dragons of War
DL11 Dragons of Glory / DL12 Dragons of Faith