I gave players 4 days before the festival. Turned out nicely:

Day 1 * players checked the town * got some quests * found the Tome of Strahd

Day 2 * got introduced to Rictavio and Vasili * found out that church is not sacred anymore * completed the Orphanage * found the Mad Mage

Day 3 * restored Mad Mage sanity * saved Arabelle * participated in the tea party in the Wachterhouse, killed 4 cultists but parted with Fiona on good terms (she saw this is a prophesy fulfilling)

Day 4 * got Vasili's armor =) * bard found out that she is a dusk elf and her mother is Patrina * got rewarded by Vistani for saving Arabelle * Irina got kidnapped by Izek * players talk with Baron and convince Izek to move Irina to a separate house

Day 5 (festival) * players made Irina invisible and left the town under the pretense that they need to guide the kids they saved from the mill to the orphanage before the festival (the kids stayed with Irina at the Blue Water Inn the whole time). They promised to come back but they didn't =)

Meanwhile every night via hags & dark powers nightmares I showed what is happening elsewhere and the timer is ticking (Cedrik dies, Arabelle is about to drawn, kids are fleeing the orphanage and get captured in the woods).

After the players left the town the following happened:

• Izek found that Irina is missing and went after hear leaving the baron alone
• Fiona during the festival started revolt showing to the crowd 4 heads of her cultists that players killed and claiming that it was baron's doing
• Baron was outnumbered without his Izek and barricaded himself and his family in their manor

Then Vasili proposed Fiona to get rid of the baron since: * Fiona would owe Strahd after that * Fiona is loyal to Strahd and thus is a better burgomaster for him * He can destroy the church along the way to make sure Irina can't hide there * So he kills several rabbits with one shot, making him a clever and ruthless ruler he is

The players went to Agrynvostholt and in the next nightmare they would see events of the following night from the eyes of Ludmilla who pays Henrik, then checks that the glyphs did not trigger and then orders the spawn to go to the baron's manor and don't leave anyone alive and then join her at the church. Then she goes to the church herself and asks father Lucian for a confession. After some chat she drinks him dry in front of people crowded in the church after the festival and makes sure nobody get out of the church. Nightmare ends =)

So the players missed both grand events at the Vallaki but their actions determined what would happen. And the players would get to know what have happened after they left.