EJB, You are asking how high is up, how long is a roll of string and what is the pretiest color... BUT here goes...
My wife bought at least 3 different books on selecting a great retirement location. (If it is good enough for retirement it is probably good enough for pre-retirement... plus you don't have to move again when you retire.) For 10 years our vacations were mostly thinly veiled retirement location research expeditions. We visited plenty of them (After decades in San Diego our climatic requirements exclude the deep south, northern new england, etc.) We visited Sequim (SP?), pronounced skwim, Washington, a rare and beautiful climate in the rain shadow of the Ho rain forrest of the Ho peninsula in Washington. We were there a week, never saw the sun, few tedious downpours but a pretty thorough misting everyday at a minimum (late summer), we called it light rain, locals call it mist and go on working outside as if it were sunny. And on and on and on for about 10 years. If we had a lot more time and took 20 years we would still not really see all the spots. We saw Fredricksberg (burg?) in the hill (ha ha , hill my backside) country of Texas. Nice but no cigar. And on and on and on... Arkansas, some nice country being bought up fast, rural areas have really poor roads often clogged with motorhomes, shared with logging trucks and locals too impatient to wait and passing on blind curves. So, what did we do? After nearly 10 years I realized that we never saw any prettier country that was as or more afordable than parts of Oklalhoma. Oklahoma's rural roads are not as nice as much of Texas but far better than Arkansas.
So we bought a quarter section in south central Oklahoma. There is a winter but doesn't last too long or stay too cold withoug a break. This winter has been way mild. Previous two winters were typical, a little snow a couple ice storms, no big deal. Note: I did 3 consecutive winters in Minot, ND and lived in nortwest Ohio for 7 years, Oklahoma has mild short winters.
Forget your climatalogical wisdom imparted by the clasic movie/book "Grapes of Wrath". Oklahoma has more miles of shoreline than Minesota the land of 10,000 lakes. Get a recent (less than 20-30 year old) map of Oklahoma and draw a diagonal line from the SW corner to the NE corner. Ignore everthing above and to the left of the line and look to the right and down. Look at all the blue (water) on the map. Check land prices, taxes, etc. Not too bad.
I'm sure there are lots of places as good, maybe some better but you could spend a life time looking and still not cover the country. I supressed the scientist in me in favor of the engineer, i.e. stopped looking for perfection and took good enough.
Good luck to you in your search,
Patrick