That's pretty much exactly what I did, except I ran to the electrical entrance ground (preferred for a number of reasons, helps avoid "ground loops", etc.) vs. a water pipe that, as others have said, could be a dubious ground. I ran #10 stranded THHN (insulated) wire all the way from the dish itself, alongside the coax cables, through the hole in the wall then located the ground block there, out of the weather. The THHN was stripped at that point but otherwise unbroken. The stripped part is what the ground block contacted, then that wire continued to the panel, about 20' in my case. Avoid any excess wire, "coils", sharp bends (as you are doing), etc. to minimize the inductance. Use some "electrical grease" at the connections to minimize corrosion.
Putting the ground block inside is not in complete conformance with the NEC. I'm not sure what code would apply for you. My spin on it is that NO residential grounding scheme will protect me from a direct lightning strike regardless of where the block is located, so that is not really the intent of the ground. This type of ground will however do a proper job bleeding-off static that will affect performance, and could provide ample protection from an EMP caused by a nearby strike which is much more likely than a direct hit. IMO, the location of the block makes no difference electrically in either of those lesser cases and being out of the weather is better. Having NO ground could have implications as far as my homeowners insurance is concerned in the case of electrical damage that would otherwise be covered, but I really don't know if having the block inside vs. outside would matter in that case.
Welcome, BTW...