I won't comment about the end....you already wrote what I would say.
The halloween sounded nice. Unfortunately, it is the feeling of being "the happy little family" that usually results in the spouse drawing away. That's an illusion and your wife also doesn't want to give you the wrong impression. It's possible for a couple to do christmas and halloween, etc, together without it meaning anything. You made the invite to have dinner and relieve her of cooking duties an obvious attempt to spend more time with her by not just taking the kids. So then the invite becomes all about her. If you wanted to save her cooking, you would have still taken the kids. Too late now, but knowledge for another time. Anyway, don't be surprised if she's more aloof now.
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt
