Actually have the tongue extended on the trailer. My local trailer shop does this all the time. He cuts the standard receiver out, puts a 3x3 tube in place and connects it to the frame of the trailer and extends it up to 2 foot past the original ball mount. This usually costs around $200-300, but it is permanent.
I just had this done to a flatbed of mine so that I could put a toolbox on the front. I needed every bit of the 16ft to all all of the atv's. Giving up 15" of deck space was not an option. Only drawback is you cannot use a WD hitch with a straight tongue.
I have a slide-in camper and tow with an 18" extension. I don't notice any change, but then again I have a 1 ton DRW.