My inclination is to let calls to the land line go to voicemail in any event — and given that our main phone, though a cordless, is across the room from where we usually spend whatever time we spend in that room, that’s pretty much the way it works out anyway. We also have a device that does include that “Block Everyone Except…” function, which helps.
On rare occasions I receive calls to my cell number from outfits that are or ought to be (in my opinion, not necessarily shared by Congress) bound by the Do Not Call list, but if I take those calls I’m quick to tell them they’ve called a cell number and then hang up. So far it’s worked every time.
I wonder if telling telemarketers my land line number is a cell, would work?