Several options come to mind. I live in Fort Myers and sail the Caloosahatchee River often. Last weekend in 10 to 15 knot winds with gusts to 20 wind from the east. Perfect conditions! The river is best sailed during the week to avoid boat traffic/wakes. Public boat ramps can be found at
http://leewaterways.com/public-boat-launches/I also like the Sanibel Causeway. There are plenty of places to launch on the bay side of the causeway island closest to Sanibel( look at google earth and this will make sense). Drawback!! Toll is $6.00/car + $3 per additional axle. Sailing on the bay side of causeway and check out Picnic Island and Tarpon Bay. You have to cross a sometimes busy channel to get to Tarpon Bay. Very good fishing in this area many times of the year. Stay on Sanibel and you only pay toll coming onto island.
Last recommendation is Estero Bay launching from Lovers Key State Park. Estero Bay has lots of marine wild life. Bird watching can be extraordinary. Not uncommon to see manatee and Dolphins. By Feb the water is "colder" relatively speaking and Manatees tend move up Caloosahatchee River seeking warmer water. I recommend stopping at Mound Key. Approachable with my TI but you may have to mirage drive it into island depending tides. Mound Key is a 30 foot tall hill of an island created
by the Calusa Indians.
If you decide to stay on Sanibel a visit to JN Ding Darling National Wildlife Refuge is a must.