Depends how bad it is. I had my eye on a soft spot for some time. Had a seal test done, leak fixed and it has not gotten any worse in the past year. The soft spot in my rv is between the bath tub and toilet- where no one would ever step anyway.
I cover mine in winter. I think it helps. The sun will do a lot of damage and a tiny water leak in your roof can rot your tt away within months. Car port is really the only practical option to keep your trailer looking new. Next best option would be a cover in the off season.
I own a 2005 Zeppelin II Z191 and love it. I have had basically no problems and my floor is solid. The unit has a higher end feel with the nicer appliances, fiberglass frontend and propane cover.
The Zeppelin does have a bad reputation for soft floors though, especially the longer units with slides. I heard there was even a factory sold floor brace modification.
The problem with the freebie, is that it will be on you to dispose of it(probably not for free) once it is toast. Replacing the flooring is not an easy task when it will be needed. Plus there is all the other costs if you want to be able to tow it.
Someone wanted to give my then 10-year old daughter a "free" horse once too. for someone without a farm, free turns into $500 month in boarding fees + everything else.
Regarding disposal... I bet someone would take the biggest pos trailer if it had one working fridge or one working ac or even one useable tire.