Fermentation temperature question and space

So I ferment my primaries in a keezer where I can keep my temperatures locked in to avoid fluctuation. I can only fit one 5 gallon bucket in the keezer at a time so I wanted to see how much temperature fluctuations affect the beer when its almost through the main process of fermenting. anyone experiment with this at all? Thanks

I ferment in my basement for a lower more stable temp. If the temp is fluctuating or a little low, I wrap the fermenter in a wool blanket and insulate it from the floor. If temps are a little high I place it directly on the floor, which lowers the temp by about 4 degrees.

If you search this forum you will find DIY projects where people have taken the door off a keezer and extended it's volume by building a foam and wood extension.

Otherwise, you can get a muck bucket, put your carboy in it, and fill the space around the carboy with water. This extra thermal mass helps lessen daily temperature fluctuations...

The critical period for temperature control is the first couple of days or so when the yeast are going crazy with all the sugars to eat. Once the majority of sugar is gone, your beer's flavor is pretty much set and you could move the fermenter out where it is a bit warmer to let the yeast continue the cleanup. I wouldn't rush to take it out (I like mine to have a week at the cool temperature) but if I needed the space, I'd have that fermenter out on the third or fourth day. The exception to this is a lager which needs the cooler temperature throughout its long ferment period.

Thanks for the replies. I'll check out the DIY projects as well.