SA, I'm against game playing. Our spouse's will see right through any tactic applied only to trick them back. Like my friend lil'G says, any actions you take have to be things you want to do for you.
Congratulations on 45 years of marriage! You two obviously have been doing something right to make it this far. Don't let him see your neediness/loneliness. Stay strong and hang in there. I don't think it will be that easy for him to throw away what you guys have.
You mentioned your house is lonely at night. Do you have any younger grandchildren who you could invite for a sleep over on the weekend? Bake cookies, play games, stay up late...
How about women friends that could come over and play cards or watch a movie?
It's great that you're busy, keep that up.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl