Ask at Reception for your kettle or phone when you get to your room and they'll bring you one. I always buy the individual milk cartons from the hotel shop. (The kind that come with a straw)
Just got back from SQL - kettle can be brought up no problems (we had one in the room but it needed replacing as someone had boiled milk in it - yuk!) and yes the little kids cartons of milk can be brought from the shop. Alternatively we walked the 5min walk to the esso garage to pick up a bigger milk and some snacks