I'm in climate Zone 28 and garden year round. Zones 31 & 26 might also provide the same capability. Looks like you have lots of options.

Here is a link that might be useful: Sunset Climate Zones

If you're looking outside of FL, maybe places like Atlanta area or Athens, Ga (UGA) or Upstate SC (between Atl/Charlotte) with mountains/lakes,Greenville, and college towns (i.e.,Clemson). Or maybe Charleston or Savannah if you want a climate more similar to FL.

Yeah, GA, a little high up in the hills, is your ticket. On a side note, last night I followed a link to the Blue Zones, apparently a well known group of five areas all over the world where life expectancy is abnormally high. They were all coastal places, although for historical reasons people in the Greek island ate little fish (they had to live high in the mountains to escape pirate predation for centuries), and another in CA was vegetarian. But what did they really have in common? Ubiquitous vegetable gardens. So build a sturdy house in your new place, it may have to last 40 years or so.

If I could be just one zone warmer I could grow (whatever) is the way i think... But then again I'm in Maine.

When I lived in Tennessee I remember listening to some of my co workers discuss vegetable gardening, heirloom varieties & so forth, and wondering what the allure was. Now I'm in Vermont, with lots of space for a garden a considerably shorter growing season, and less income to spend on something like a greenhouse. That's life!

You might as well stay in Sarasota year around or move high into the mountains for summer. At lower elevations the mid Atlantic and southeast are hot and humid in summer just like Florida. You might find better soil in another spot but the climate will be about the same in summer unless you head uphill.

I highly recommend Athens, GA. The university as the trial gardens, and the state botanical garden is close. There are quite a few nurseries just outside of town, and I suggest you check out Winterville, GA
The climate is nice in Athens.
It's a college town with all the conveniences.
Tons of shopping for the Ms. and not all that far from Atlanta.
Winterville features new homes in subdivisions but there are older homes and lots in the area.
Several great nurseries around the area.
Loads of gardeners!
Reasonable drive.

My parents lived in Sarasota for many years (but that was many years ago!!).

Here is a link that might be useful: Thyme after Thyme in Winterville, GA.

I guess I'd be remiss if I didn't welcome y'all to pay us a visit here in Chattanooga. Plenty of rural land around (I'm sitting on 20+ acres of mostly forested land, but there's plenty of wide open pastures as well), lots of pretty scenery (we were named Outdoor Living's #1 city to live in a few years ago), and some nice historical sites (Chattanooga Choo-Choo, Rock City, etc).

Several big shopping centers (Northgate and Hamilton Place malls), and we're surrounded by mountains and high plateaus that mean we have fairly mild weather year round (almost all really bad weather, tornado bad, gets blocked by the mountains or worn out by the plaeau). As for warm weather, well this town virtually shuts down if the ground so much as turns white, so you can see how much snow we get. =)

grandad, you are right about sunset 31 & 32.
I live just in 31 in Columbia,S.C., if I read your map right.
I garden year around, not tomatoes, but winter stuff in the winter & everything else in summer.

I grow here in Marvin NC. I am about 30 minutes to downtown Charlotte, 30 minutes to UNC-Charlotte, 30 minutes to Winthrop U., right on the NC/SC state line. Our winters are mild. I grow something every month in the garden, I have plants/shrubs blooming just about every month of the year (Mahonia and Camelias are blooming now. We have a few days every winter that are too cold for me to garden, and a couple months in summer that, if I didn't have a pool, would be too hot and humid for me after around 10am. All in all, you can find some commuter n-hoods around Charlotte that offer anything you want and a hub airport for USAir. I've heard that the Raleigh area has some wonderful nurseries and the JC Ralston gardens at NC State U are to die for.