I'm considering running the Rise of Tiamat module, but I'm not sure what kind of time commitment I would be asking of the players.
I expect to run sessions of 3-4 hours on weekday evenings. There is the possibility of a longer weekend session, but it turns out to be hard to schedule regular social meetings for several adults.
The module has nine 'Episodes' and six optional 'Additional Encounters' listed in the introduction. I'm confident any group I put together will end up off the expected track at least once (the book even agrees), but for the purposes here let's assume we do all nine Episodes and three of the optional encounters. I'm just not sure how long each Episode is expected to take. If each is 1-3 sessions, then I'd be looking at 9-27 sessions, rounding to a high of ~30 with the extra encounters.
Yes, this module is based on Milestone advancement. However, an XP-basded comparison approach seems in order. DMG 84 indicates an Adventuring Day is 6-8 medium or Hard encounters per day. Doing some envelope math, it seems that getting from level 8 to level 15 requires about 18 full Adventuring Days. This works out to ~120 medium or hard encounters. Assuming one per hour, that's 30-40 sessions.
Am I really looking at ~30 three to four hour sessions to complete the module?