Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Grand Rapids to Reykjavik Keflavik Intl Airport as you normally would.
Due to multiple factors, expect to potentially pay more when booking in November. For low rates, October can be a great choice for travel to Reykjavik Keflavik Intl Airport. Flights to Reykjavik Keflavik Intl Airport from Grand Rapids in October are about $1,054 on average during October, but can be found for as low as $624.