Every time I try to shop around I am shocked at how cheap my existing State Farm coverages are. Keep all your policies in one place with an umbrella and it gets cheap fast. I have 4 vehicles, an Airstream and 3 homes insured with state farm. Full coverage, 250/500 liability vehicle coverage monthly with $1M umbrella is under $400 including an airstream. My additional coverage for the 2017 FWC, when I had it, was like $8 a month. For reference, truck campers are FAR less expensive to insure than travel trailers.
I've never seen a quote from a competitor that was less than double what I pay now.