Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Bozeman to Duesseldorf Intl Airport as you normally would.
Bozeman Gallatin Field (BZN) is the airport you will fly out of if you book a flight from Bozeman to Duesseldorf Intl. You should not have trouble finding flights to Duesseldorf Intl from Gallatin Field; the airport handles an average of 0 outbound flights to Duesseldorf Intl per day. You should also have plenty of airline options to choose from since 0 airlines have flights from the Bozeman airport to Duesseldorf Intl. It is only a 8.7 mi journey to Gallatin Field (BZN) from Bozeman’s city center.