There are a 2 igloo hotels in Finland. One is the Arctic Resort Kakslauttanen (nearer to Ivalo, further north than Rovaniemi) and the other is the Arctic Snow Hotel (the one I stayed in) which is only 27km away from Rovaniemi City Centre.
The hotel is not very big, there are a total of less than 40 igloos (of which 5 are family igloos). Each igloo is 20 Sq meter (houses up to 3 person) while the family igloo is 35 Sq meter (houses up to 5 person). There is a snow hotel as well but it is only operational from late December until February. During our stay there, the Snow Hotel is still in the midst of construction.