Why prices spike
Between mid-December and early January three streams arrive in Bali at once: Indonesian school holidays, the Australian summer break, and European travellers escaping winter. The result is the highest occupancy of the year.
What changes
Room rates run two to three times higher, and many hotels impose minimum stays and compulsory New Year's Eve dinner charges. Popular restaurants need reservations days ahead. The Canggu–Seminyak–Kuta corridor can gridlock in the late afternoon.
How to work around it
The only strategy that works is fixing your price well before the window opens. Delaying a booking over Christmas and New Year almost always ends in the top rate or no availability at all.