They don't start much earlier than other hotels. I have never had breakfast there which isn't in the Scandic by the way but in the adjacent airport restaurant (so I suspect it is not the normal Scandic breakfast). I have stayed at the Gateway when my flight has left like 630 and I have then just missed the breakfast. I have got a coupon for an airport cafeteria instead, which has given me something like a bread roll, coffee, juice and a yoghurt. But if your flight leaves at 8, you'll have time to try the regular breakfast.