OK, just to follow up on my own experience here.......
Bad news is, if you want to keep your landline number, I would advise you not to use Verizon prepaid phones to do it.
While reanimating one of my zombie Verizon phones was easy, they would not allow me to port my number in order to do so, because they claimed I wasn't the "account owner". Even though I personally set up the account and did not give anybody else permission to do anything with it. So who else would be the owner?
This of course reminded me why I dumped Verizon in the first place, because their customer service probably ranks second only to Comcast in terms of pure suckage.
Good news is, since Google Voice didn't have any phone numbers available in my area, at least Verizon was able to provide that much. And the port from Verizon to Google was easy enough, and took just over 24 hrs.
So, total time for the whole process = roughly 48 hours.
Total cost = $15 to Verizon (minimum they would allow for prepaid minutes) + $20 to Google. = $35
Kinda wish I could have kept my old number, which ironically came from Google Voice (then known as Grand Central) in the first place. But what the hell..... 7 years is a good ride for phone numbers these days. Too many telemarketing calls recently anyway.