I get that the grass is always greener, but there's a major pile of rock between you and the Bay Area's Sutro tower. It's one thing if you live in Vacaville or somewhere served by BART, but you've got local stations. While the CM-3020 can do big miles without "edges", I doubt it can do red zone stations reliably and that's not a good situation for any DVR.
I repeat my concern that TiVo may not be particularly graceful with your configuration in terms of guide data.
Fellow member larrykenney was DXing from the Bay Area towards Sacto with some very narrow beam antennas. teachsac might have some insights.
Post-repack, the situation may get a little dicier as there appear to be some channels in common as well as several of the San Fran channels entering into sharing agreements (presumably losing some subchannels). The big four look pretty safe except for maybe NBC out of San Jose but it remains to be seen what will distinguish the San Fran stations going forward.