Going for a drive is good, being mysterious. Maybe get a book that is interesting, but somewhat out of character for you. One about travel, maybe? Somewhere YOU always wanted to go? Or a new hobby that would still interest you, even if things don't work out with you guys. A little 180.
I don't think I would go into another room too much though. It could look like "the bunker" mentality.
Just act as upbeat as you can around her in your own home.
