Hello Eric,
" I am curious in knowing how long people have been able to keep their annuals going for. "
I keep my outdoor zinnias growing and blooming right up until a killing frost or freeze. I am in Kansas, which is in the Midwest, and we usually get a killing frost sometime in October. You are in Florida, so you may not even get a killing frost, so all bets are off with you and zinnias. These are a couple of frost-bitten zinnia blooms from a previous year. Click on the pics for larger views. Hitting the F11 key removes your browser's heading material, which makes more room yet for the photos. Hit F11 again to get your headings back and close the big photos with the "X" in their lower righthand corner.
I would be curious to know how zinnias do in your part of Florida, which might be frost-free.
ZM