Perhaps the answer to the problems the GOP is facing could be running up margins with the whites, particularly blue collar whites who didn't show up to vote this time and who used to vote Democrat. There is no real reason why white working class would continue to vote for the Democrats in the next election.
Perhaps the GOP could forego NM, CO, FL and VA for a more populist message in PA, MI, WI and MN?
That would have to be a strong anti illegal immigration message.
I agree this will be their natural inclination - basically trying to apply the Mississippi/Louisiana situation to the US as a whole.
However, it still puts them at a slight disadvantage if Georgia and Arizona begin to break lose (about as likely by 2020 as the GOP taking over Michigan, eh what?)
Even if the GOP could break lose the Dem hold on the 'rust belt' (or white working class belt) before they lose GA and AZ to swing status, it still leaves them somewhat behind (and that's not even mentioning that the upper midwest/PA will be losing electoral votes in 2020 while GA and AZ will be gaining):