Burt (John Krasinski) and Verona (Maya Rudolph) are about three months away from having a baby. When Burt's parents decide that they are going to move to Europe for a couple of years (weeks before the baby is due), the couple decides they have no ties to the area they are living in and embark on a cross country road trip to find a new home. Along the way they meet several different couples who all have different views on love, relationships, marriage, and most importantly, parenting.
The whole journey, Burt continuously asks Verona to marry him. She declines each time and we find out that her parents both died when she was in college (we don't find out why) and she just doesn't see the point in getting married.
In the end, they both realize that what they need to truly be happy is each other, and not to move someplace because they have friends or family there or to get married.
They end up moving into Verona's parents home that she and her sister have been renting out ever since their death. As they sit on the back porch looking out over the Mississippi, Burt says that he thinks this place will be perfect for them. He asks if she agrees, and she replies, "I hope so, I really f*cking hope so."