I would say you have a ZERO chance of getting a good HD signal there. The Ka-band frequencies used for the HD signals are more susceptable to signal loss than the older Ku signals are, and those trees are currently plenty big enough to block the signal. And those trees are only going to keep growing; expect to lose your 101 signal soon.
Then there is the *current* requirement to get 110 and 119; both of which will be 100% blocked today. No HSP installer would touch that install, because it's going to be an automatic QC fail and chargeback. In fact, newer receivers won't even activate without proper line-of-site. An independent might do it, but probably not.
Your possible solutions include either major tree trimming or relocating the dish to the roof, as high as possible, or to the other side of the house, LOS permitting.