When I make lagers, I do the starter at room temperature. After all, I am growing yeast, not making beer. BUT I make it at least a week in advance, and add another pint of starter wort when the first one finishes. Then when it's completely done, I refrigerate until the yeast is at the bottom and only clear spent wort is at the top. I then decant the spent wort, and pitch the yeast. When I pitch the yeast, the yeast is at 48 degrees, and the wort is at 50 degrees. I find it gives me the best start at fermentation.