Yes, Panettone and all leavened doughs can rise at room temperature (19°C - 20°C, 66°F - 68°F). The proofing time will obviously be longer: 18-20 hours for the first dough fermentation and 10-12 hours for the final proofing.
The main advantage of a long fermentation is reduced consumption of sugar in the dough. As a result, the Panettone will be sweeter.