On the website of The Icelandic Meteorological Office (Veurstofa ═slands) you find cloud cover forecast for next few days and Aurora forecast which shows expected activity of the aurora at your selected date. This you can use to find the best area in Iceland to see the Northern Lights for next days. See http://en.vedur.is/weather/forecasts/aurora
In H˙na■ing vestra you find many good places to stay, close by the nature and far away from the urban light pollution. Where you can see the northern lights at it best.