As far as I know TV mounts are a standard size, so as others have said the limiting factor will be weight limits for the bracket and the wall it's fastened to, and the amount of physical space available.
We have a 12v TV for the caravan, and we've never used it in 12v mode - however it gets used for lots of other things, including an extension laptop screen (I'm staring at it right now) and a remote video monitor for Mrs Gozza's dinner theatre business, when we HAVE used in 12v mode.
As far as storage and transport is concerned we have a TV transport bag, can't remember the name of the company it came from but they advertise in the caravan mags, company name is something like "Bags for Everything". Given that our previous caravan TV died of a broken screen in an in-transit incident (while being carried in the manufacturer's original packaging) I thought it was a worthwhile investment, and so far in the eight-or-so years I've had it, I've not been disappointed.