By the looks of things, the grass isn't quite so green in Iceland. The one picture I've seen was of a generally brown, cold- and wind-burnt set of fields which is not untypical for what the Brent encounter when they arrive in April and early May. A very marked contrast from the rich grass they last munched before they left Ireland.
Our migrant goose researchers are also staging this month in western Iceland, catching and tagging Brent and reading rings. This spring is the 12th spring there has been a significant UK/Ireland involvement in the Icelandic staging grounds. I expect we'll get a few reports as the weeks go on though, from bitter experience, the fieldwork days are very long and there isn't much time for typing on a computer!