I ran LMoP over Roll20, and I used this fan-created map for the Wyvern Tor encounter:
http://rpgmapshare.com/index.php?q=gallery&g2_itemId=56089
(There's one for Old Owl Well too:
http://rpgmapshare.com/index.php?q=gallery&g2_itemId=56085)
Cool. I'm definitely going to include a lone orc for them to encounter ahead of time,
I used that encounter as suggested on the WotC forums, and it worked really well. The players, having just come from Old Owl Well and having a healthy respect for 5E combat, decided to ally with Krokk. They killed the sentry and then sent Krokk in to lure out the chief orc and his ogre buddy. After the PCs dispatched the two of them--a relatively easy fight, though not a complete walkover--Krokk, as promised, led the rest of the orcs away.
... although I'm not entirely sure how it would work for him to make a play for the leadership of the band. Orcs value strength, and if this guy isn't strong enough to beat the leader himself - if he needs help in the form of the PCs - then I can't see the others being willing to follow him.
Here, I borrowed a page from
Scrivener of Doom's blog writeup and had the orcs searching for some relics of the old kingdom of Uruth Ukrypt in order to challenge the status quo of the Many Arrows tribe. I didn't like the idea of repurposing Cragmaw Castle, as the blog proposes, so I left vague exactly what they were searching for. Anyway, the orcs had found nothing so far and were starting to feel that they were on a fool's errand. Only Brughor's insistence was keeping them there. Thus, if Brughor were removed, Krokk was confident he could persuade them to go back north. Whether he can hang onto his rule any longer than that is beyond the PCs' concern (unless they should choose to make it so).
This has a nice parallel with the Red Wizard searching for artefacts at Old Owl Well, too, and suggests that the whole area is potentially crammed with interesting treasures waiting to be discovered.
On a side note, am I the only one who finds it a bit odd that wyverns would've nested in a cave at the bottom of a ravine? I would've thought they'd have preferred to nest up near the top of the rocky outcropping.
Does it say the nest was in the cave? I thought it was at the top of the hill. After all, it's the hill (tor) that's named after the wyverns, not the cave.
Funny how the adventure gives you pressing business and then assumes you'll ignore it to go after sidequests CRPG style.
Well, you find out later that King Grol and Vyerith had gotten stalled in negotiations for the terms of handing over Gudrun Rockseeker. Those could easily last for days.