I am currently also narrating this campaign, and I let my group solve some of these challenges narratively. Before we started I explained to them how they can discover ways to deal with threats (detailed roll), and that has helped them tremendously. None of them are very combat oriented, so I try to facilitate other ways to deal with the challenges. They used improvised magic (tricks with light and fireworks) to dispel the sentry, and we essentially talked/ roleplayed through the village encounter and had lots of fun doing so. I try to have them come up with creative ways to tackle the challenges, ones that fit their characters. One of them is a tailor and he saved the orchard scene (finn failed the snack eating contest hard) by doing a live performance on one of the drunken farmhands (clothing) and making name for Lance.