Great story! I have a similar one, but in the opposite direction. Last year, my husband and I carried separate insurance on our cars - me with Progressive, him with Safety (legacy policies from our pre-marriage lives). 1.5 years ago I had researched costs and couldn't find any better deals by combining coverages, so we kept our pre-existing policies.
When my 6-month policy with Progressive was up about two months ago, they informed me they would be raising my premium by 50%. (!!!) I had no accidents, claims, or changes that would justify the change, so in my rage at this ridiculous increase, I started researching alternatives.
Lo and behold, Liberty Mutual, Plymouth Rock, Allstate, and Safety couldn't do better than our total costs had been under our separate Progressive/Safety policies. But Geico could: their quote for both of our vehicles was $1100/year less than we had been paying! The only change to our coverages was that I increased our collision & comprehensive deductibles from $500 to $1000.
Geico has only recently started operating in our state so they weren't an option two years ago. But they are today, and by paying for 12-month policies up-front and raising our deductibles, I saved us $1100. It's kind of shocking, really.