thats a great design for a bigger antenna...
another thing that i have done on many of jobs with dual-tuner boxes, is to combine the UHF antenna, and my TV2 signal on the same line to the other room, then in that room split them back apart...
so far it has worked every time
on one job i did... from the back of the receiver, the remote jack, and TV2 out jack into a splitter, then into a diplexer with the sat feeds, then down to the basement through the other diplexer, then out another 125 feet to the metal garage, where i used a splitter, one side to the TV, the other side with the little factory antenna on it.
total it went through about 200 feet of coax, two splitters, two diplexers, and two wall plates... and ended up in a metal building that before the remote didn't work at all unless you had the door open on the side facing the house....
now it works amazing, just as if it was in the same room, there is no delay at all