Temperature control is rather important to bottom fermenting (lager/pilsner) yeasts. Most of them like the low to mid 40 temp range. If you let the temp fluctuate, it's going to wreak havoc on your beer. On thing you may think about to control your temps is making a fermentation chamber. There are several in the DIY section.
I'm on the NW side of the city and have an unheated yet insulated back porch. I found my temps get to about 5-10 degrees higher than the outside temp. I made a simple box out of 1 inch pink styrofoam to keep the temps relatively stable. I'll be putting a 6 gal batch of Kolsch in there tomorrow and monitor the temps for the next several days.
On Deck: Research in progress....
Primary: House Arrest Tripel
Primary: Deception Cream Stout
Kegged: Kolsch 1.0
Kegged:BrewNinja's Spotted Cow Clone