I would think any lift on a travel trailer would dramatically increase its instability as well as that of the TV. You did not specify the type of TV but I wouldn't even think of doing something like that without a DRW vehicle.
As far as lifting it, which I wouldn't recommend, the only thing I can think of is a lift block under the springs. They are used at times in lifts for vehicles and since you aren't going to find a "suspension lift kit" for an RV this may be the only choice. Finding blocks that would fit would be challenging if not impossible. Again, doing that would make your trailer very unstable IMO. A new shank and leveling the trailer may be the best you can do.
Everything in life has its limitations. Maybe the trailer and the place(s) you want to take it are just incompatible