As both a vacation home owner and a timeshare owner let me give my feedback.

Vacation home: I typically like to book out as far as possible for at least 2 weeks at a time. Considering all the expenses with a home, cash is king. That said, if I ended up with a vacancy in the next week or so, I would consider miles or other points I could use. But it might be a lot of points! Right now I have a long term tenant in SW Florida.

Timeshare: I think you might have a better time trading for a nice timeshare. I also own 2 timeshare units and often end up with extras in RCI the trading company. These expire if not used. One complaint some timeshare owners have is the cost to fly there. That could be a win win. But remember there are real expenses with a timeshare as will. Many of maintainace fees are near $1000 for a week plus the Rci trade fee. You best bet to find willing traders may be a timeshare site like TUG. Craigslist might also help you find timeshare owners looking to rent there units.

Feel free to pm me if you like to discuss other ideas I might have.