If I was the GM of a VR game like this I would make it so 1 guild can occupy the dungeon for 1 month and a 2 month cool down if any guild wants to occupy the same again that includes the previous guild 

🎵 Truck-kun where are you,
Truck-kun where are you,
Truck-kun where are you I need you right now🎵
🇯🇲
Sing to happy birthday song*
Truck-kun where are you,
Truck-kun where are you I need you right now🎵
🇯🇲
Sing to happy birthday song*