If you plan on suggesting to him that he should move out, you've gotta be prepared for him to do just that, and it won't necessarily make things better. In my own sitch, Since H moved out we've had little contact and only seen each other a handful of times. We have no kids, or anything that forces us to have contact of any kind, and as a result, we're now basically strangers. Haven't heard a peep from him at all in almost a month, unless you count the letter from his L. So unless you're willing to risk the same thing, I wouldn't go telling him to move out.
Stop txting him to ask when he's gonna be home. Just be as upbeat and supportive as you can be when he is home. It's really all you can do. It sounds to me like OW is getting all kinds of desperate in an attempt to keep him hanging on. Hopefully he'll get to a point where he feels like he needs to really pull away from her, and when that happens, you have to be the favourable option that immediately springs into his mind.
Me:30 H:30 Together:10yr H left:Oct3'06,couple weeks before 5th wed anniv. No Kids OW bomb:Jan19'07 My thread: He filed.