I have been married for twenty-one years. I have three daughters. The two oldest have had a child (one each) within the last year. This has put a huge burden on myself and most of all, my wife. She spends a lot of time caring for the grandchildren. This is something she does not want full time. Both our daughters still live with us. I have asked them to get their own place. This has led to major problems between my wife and me.
Conflicted Husband and Father
In the face of your wife's and daughter's opposition, your only chance to have the latter move out would require taking a very strong position that might force your wife to choose between her husband and daughters. This stance would be perceived as extremely harsh by your family and may seriously harm your relationships with them. I therefore would not recommend this strategy.
The problems between you and your wife are, I assume, related to your attempts to change her, to advise her regarding her behavior toward your children and grandchildren. I advise that, as much as possible, you stop trying to change your wife. If she complains to you about, for example, the burden she is experiencing, listen sympathetically; do not even talk to her about an alternative. She knows what it is.
Instead of focusing on her, define for yourself the kind of father and grandfather you want to be -- how much you wish to give and what your limits are. When you accept your wife, you may no longer be a target of her anger. This may enable her to eventually reassess the situation. It is only with her as a partner that you will be able to move toward a less demanding nest.