Moderator, SkyTeam and Germany
Join Date: Sep 2001
Location: FRA/STR/NUE
Programs: BA, LH, KL, EY, IHG, Marriott, Hyatt, Hilton, Radisson, H Rewards
Posts: 5,965
... in 1st class usually there will be ample choice of seats without reservations to choose from. Outside the busiest hours like Monday morning or Friday afternoon probably 50% of the seats will be available/not reserved.
You can reserve online, or with any of the red/white ATMs that you find at any station with DB service. Reservations for ICE trains can be made up to 10 mins before departure.