You're doing it right, my man. Fermentation control is more important than fancy equipment or even all-grain recipes. I'll bet your beer is great.
Sounds like you're patient and deliberate with equip purchases, so you've got the tools to add another fridge/controller for a fraction of $250. With baby on the way, its a good time to ramp up cellar capacity. You'll need supply in those first few months!
Scour Craigslist until you can find a used dorm room fridge. If not free, I can usually find them for under $100, and sometimes they pop up for much less. You can usually haggle, so I'll bet you can pick one up for $50. Just make sure it fits a bucket/carboy.
The $150 Ranco 2-stage temp controller is a fantastic out-of-the-box solution. However I built my last 2-stage temp controller for about $50, and you can cut more cost by picking everything up via Amazon. The electrical DIY scares some people away, but its not difficult with proper instructions.
I haven't written up my build (yet), but I'd be glad to help you out. Shoot me a message if you have questions or want pics, wiring sketch, parts list, etc. I need motivation to put it all together anyway.
These references should be a good start:http://mostlyharmlessbrewing.com/2013/08/24/keezer-temp-controller-stc-1000/http://brewprof.com/weekend-diy-homebrew-project-dual-stage-temperature-controller-stc-1000/2/
If you go this route, I have a few suggestions from my experience:
1. You might try to find a STC controller that reads in Fahrenheit. They are a few bucks more, but I still can't get used to the reading Celsius, especially since my other controller reads in degF. Plus: 'Merica.
2. Though all of the other builds I found didn't, I added a relay to switch on the fridge rather than directly switch from the controller. My controller relays have a 10 amp max, and the max draw from these fridges can be higher than that.