Downtime in Aron's Bowl

Now that the group has reached the Upper Valley, the end of their quest is literally in sight. Getting there promises to offer many more challenges, however. For now, there is a last opportunity for them to engage and interact with other humanoids in a "civilized" social setting. This is a part of the adventure path where I think it works better to step back and allow them to experience their surroundings a little more deeply.
I think with the fine edge between order and chaos, there is a great opportunity to work up NPCs and have them interact with the party. Whether as shopkeeps or tradesmen, or as other adventuring types in the street, there are good opportunities to play up the personalities and enjoy some out of combat experience. This might be a good opportunity to try out some of the rules on downtime activity.
Once the party leave the town of Aron's Bowl, they will be on their own until the culmination of the adventure. Their access to stores, supplies, scrolls, potions, etc. will disappear. There are a couple of small farming villages further up the river and across the valley, but they will have little to offer adventurers other than food and very basic supplies such as rope and tools. Due to this, the players should be encouraged to take advantage of their time in Aron's Bowl. Allow them to assess their characters, tweak any supplies and preparation as they wish, and prepare for the next phase of the adventure.
The access to miners can offer further options for side treks to defend or assist at the mines in the mountains surrounding the valley. The party can use these chances to gain further gold or experience. The balance of morality in the town can also lead to direct confrontation with other adventuring parties. The groups can interact in any way they choose, without too much fear of grave consequences. If they act too aggressively or with too much violence, enough people will rally against their actions to drive them from the town, but with no central governing authority, even that is a thin punishment.
I think the best way to handle all of this is to put the matter into the players' hands and let them direct the flow of the game for a time. If they get too far afield, or beyond what you wish to allow, use the lawless nature of the area to force them back to themselves by having the dragon attack the town, or a band of orcs roll down out of the mountains to threaten the town or one of the lucrative mines. Introducing a universal threat will force them to respond in a more focused manner, and get them back to traditional gaming concerns.
I do think one good, involved side trek would be fitting before taking off after the main goal. It would also provide a good opportunity to suggest an alternate path to the dragon's lair by picking their way across the reeking fen stretching up the northeastern spur of the volcanic range. Home to dark horrors and noxious, poisonous fumes, the fens also offer an unguarded approach to the dragon's home. My preference is to have a large force attack one of the farming towns, then flee to one of the mines in the eastern range.The ward bosses will recruit the party, among others, to pursue and eliminate the raiders.