This business of successfully putting on a life vest/jacket after you have dumped in the water is highly a function of one's age, weight and physical condition. I doubt I could swim any distance at my age and condition without a life jacket, I probably can't swim very far even with a life jacket, and my physical strength and dexterity have been vastly diminished by age.
My favorite vest for warm weather paddling is my
Kokatat SeaO2, which is a hybrid vest. It has 8 lbs. of foam buoyancy and can be pumped up to 22 lbs. buoyancy either with a CO2 cartridge are by about ten blows into a breathing tube. I took the cartridge out of mine. The vest is so light that I barely notice it even in hot, humid weather such as Florida's. If I am going to make a crossing or if wind waves increase, I'll blow it up to full capacity buoyancy as a preventive measure; and then deflate it again as conditions change.
I have tested it in warm waters by deliberately falling out of the canoe and successfully blowing it up to highest buoyancy via the breathing tube. The 8 lbs. of foam is enough to buoy me up while doing so. That's as much risk as I'll take with not wearing a PFD.