I don't know how your setup is in the 23SS with the tv and 12v outlet, but this is how I use my 500w inverter.
I put industrial duty velcro on the underside of the cabinet where my tv and DVD player are mounted.
I attached the opposing velcro on the bottom of my inverter and use it to hold it in place while we're using the tv to watch movies.
My 2012.5 Roo 233S has a 12v plug next to where the television plugs in, so I use it to power the inverter. This seemed to be the easiest setup for us, and we simply remove the inverter and store it in a cabinet when not in use. I considered leaving it velcro'd to the cabinet, but the underside wood is too flimsy and the bouncing during transport proved too much for it. Fortunately the velcro gave way and not the "wood" it was attached to.