Thanks. What if I were to do the following:
1. Switch the numbers now between one of my existing phone lines and the number assigned to my iPad.
2. Cancel that phone line now, before the new phones arrive.
3. Activate the second BOGO phone when I get it using the newly assigned number.
4. Swap the numbers between the second new phone and my iPad.
Could that work?
Following up on this. I did not cancel a line yet, but I did successfully swap the new number (and the obligation to pay in full) associated with my second ("free") Xr to the iPad on my Verizon account. So, now the old iPad number is assigned to my daughter's old 6s, which we're no longer using. I'm going to wait until the first credit appears on my bill before cancelling, but it certainly appears that I'll be able to cancel that line with no consequences.