[mtownsend]

Basically a couple of people told me the adjacent channel was going to be the primary problem for reliable reception of Ch. 17. However, since I am getting it reliably every night and into the morning for a few hours, I would have to believe that may not be the case.

If the signal improves every evening, then it is most likely benefiting from tropospheric enhancement. This phenomenon helps deliver more signal to you each night when the upper atmosphere cools off and the air near the surface gets warmed up by latent heat from the Earth.

Since you have a 91XG, you might want to take advantage of the "up-tilt" feature of its mounting bracket. You might be able to get a little bit more signal on average if you point the antenna up toward the sky a little bit (like 10º). This puts the main frontal lobe of the antenna pattern up higher and might move some of the back/side lobes down into the ground a little bit. The difference might not be that much, but it doesn't cost anything to try since you're already set up.

There are a lot of trees surrounding the property and I think that is the real impediment aside from the somewhat hilly terrain between my home and the tower.

This is another reason to try experimenting with turning the antenna a little to the left or right. Signal reflections off of trees, terrain, or buildings might be adding enough multipath interference to make KMIZ intermittent. By rotating the antenna a bit, you might be able to pick out a slightly cleaner version of the signal.

At the same time, this can potentially improve the adjacent channel interference situation with KCPT.

I plan to run a shorter cable run into the home and replace the RG6 with RG11.

Since you have a pre-amp, the cable loss from the amp down to your TV will make almost no difference at all. This cable loss occurs after the signal has been boosted by the amp, so you are unlikely to notice any difference switching from RG6 to RG11.