Whether it's viable or not (and in this instance that's the same as 'affordable') is entirely subjective and there isn't a definitive answer to the question.

There are a lot of people for whom a Florida holiday has never been viable and a few lucky ones for whom the price is always going to be irrelevant. The rest of us are in-between those extremes and have to decide where our cut-off point is, based on our own circumstances at the time.