I've no answer to the VoIP part, but I kept the wife happy by moving our home number to a cell plan and sticking it on an el-cheapo phone.

It never leaves he house and is connected to:

https://www.amazon.com/PANASONIC-Link2Ce...7031&sr=8-4

If it's a smartphone, install youmail on it for spam blocking and Bob's your uncle.

As an added bonus, I hooked my wife's cell phone up to the bluetooth on the second identity so when her cell phone rings, all the phones in the house ring with her ringtone and she can answer anywhere. Even if it's in her purse 3 rooms away. Ahem. Not that that happened all the damned time.

It's worked out pretty well.