Sally Hawkins and Catherine Keener have jumped on the How and Why train! Says Hollywood Reporter:

Should the pilot earn a series order, Hawkins -- following lengthy negotiations -- would be a series regular and play Yvonne Hesselman, Goodman's wife and the mother of their triplets. The demise of her husband's show has put a strain on their marriage, and the couple is pretending that everything is fine. Keener will guest-star as Alice, though further details about her character are being kept under wraps.

[...] Production on How and Why begins in the spring in North Carolina. (Source)