I feel pretty bad about wanting to move away from my widowed mom to spend time alone with my wife in a new city
Why do you want to move away from your mom?
I want to live with my wife alone.
Your mom shouldn't expect their married child to stay with her forever. She needs to cope on her own.
I'm going to think about it and make a decision later on.
I think it's good that you want to give it some more thought. It's a pretty big decision that you don't want to make on a whim.