To my mind, Clearwater is particularly egregious. They have a huge seasonal market - and the "season" is the winter. I have to believe that lots of off-season apartment rentals are out there.
It seems to me that the organization should simply long-term lease blocks of apartments - they know how many players they'll have, they know how much space they'll need (approximately). So in Clearwater, lease the properties long-term, and then sub-let them month-to-month in the winter, to snowbirds.
In the northern towns, it's a bit more challenging - the Phils want spaces from April through September. If the town in question has universities (Allentown/Bethlehem?), there might be a synergy with student rentals. (Not so much in Reading or Lakewood.)
But the Phils should take the leases - a mix of one-bedroom and two-bedroom apartments. Single players are assigned, two to a two-bedroom apartments (everybody gets a bedroom). Married players get one-bedroom units; married with kids get two-bedroom units.
These blocks of apartments are leased in advance of the season, with enough space to account for movements in and out. If the mix of one- and two-bedroom units doesn't match the player mix, a single guy with seniority might get a private one-bedroom unit. The organization actually pays somebody to manage all this.
If we're talking about a 30-year-old AAAA guy with a wife and four kids...that's challenging, but somebody is tasked to solve that problem (ends up being a house rental, probably).
If I were the GM, I would consider actually acquiring (purchasing, not leasing) apartment blocks. Short-term off-season leases might be possible to generate some revenue; even if they aren't, it's a real estate investment that will likely appreciate over time.