The notice, "
WARNING: Address was only resolved to street level and might not be that close to your actual location. For more accurate results, try entering a specific address or coordinates." in the heading of your TVFR prompts me to ask that you use the
Interactive TV Maps to locate your site, then generate a TV Fool Report using the button available from that page. Be sure to set the AGL appropriately. That will give us confidence that your predicted signal levels are as accurate as possible.
At this point, I'm not certain an attic install is going to be able to satisfy your needs. Hopefully the more accurate TVFR will have a more favorable prediction.