Even in Colorado, the "socially moderate, fiscally conservative" Republican is not a winning strategy. You can't hold Trump's gains in southern Colorado with that profile, and the suburban types you'd want to pull in are too far gone.
I pretty much agree with this. 2018 showed that the Democrats are not completely dead in Southern Colorado. I suspect Hickenlooper would win those counties against Gardner, and would definitely do as well as Polis, and maybe even better, in Denver and its suburbs. Gardner is also not going to do as well in El Paso, Douglas, Mesa, and Weld as he did in 2014, even though he will still win them by double-digit margins.