Two years have gone by since Tom Baker stepped down from his role as head coach, yet the implications of this pivotal choice continue to resonate throughout his family. His wife, Lorraine, has just completed her high school journey and is now interning at Allure magazine in New York City, marking a significant transition in her life. Meanwhile, Nora has tied the knot with Bud McNulty and is expecting their first child, prompting a move to Houston, Texas, where Bud has found a new job. As these family dynamics evolve, Tom feels an overwhelming yearning for unity and closeness with his loved ones.
To bridge the growing distance, Tom convinces his family to join him for one last vacation at Lake Winnetka in Wisconsin, their former cabin now owned by Mike Romanow, which serves as an enchanting backdrop. However, their tranquil retreat is soon interrupted by the arrival of Tom's old adversary, Jimmy Murtaugh, who descends upon the lake with his crew of eight children for a summer getaway. Jimmy, known for flaunting his wealth and accomplishments, can’t resist the temptation to tease Tom about his parenting style, suggesting that Tom's more laid-back approach has hindered success in his children.
As the tension between the two families simmers close to boiling point, a cascade of mishaps begins to unfold. Mark inadvertently triggers a backpack full of fireworks, inciting panic throughout the lake community when it leads to a boat explosion. Later on, Kenny and Mark’s joyride in a golf cart takes a disastrous turn, crashing into the tennis court. To add fuel to the fire, Sarah's attempted shoplifting at a local gift shop exacerbates the mayhem.
Jimmy’s incessant reminders of Tom needing to reinforce discipline among his children only stoke Tom’s frustration. This ultimately culminates in a heated clash between Tom and Jimmy, who decide to resolve their differences during the high-stakes Annual Labor Day Family Cup. Unbeknownst to Tom, his children are struggling under the weight of his rigorous training schedule, which could jeopardize their relationship going forward.
As tensions climb during the family getaway, Sarah and Elliot’s secret movie outing to see Ice Age is exposed by their fathers, resulting in a humiliating confrontation that leaves them filled with anger and resentment. When they return to the Baker cabin, Sarah’s fury boils over, leading her to refuse participation in Tom’s Family Cup plans. The other kids share her frustration, upset that Tom has infringed on their trip with his fierce rivalry against Jimmy. Kate reflects on how the two families have grown increasingly divided because of their differing parenting philosophies, leaving everyone to ponder if reconciliation is possible.
As dawn breaks over the picturesque backdrop of the Cup, Tom arrives to find Kyle and Nigel, the last two participants, ready to spark their competitive spirits once more. Just as it seems like the rivalry is ready to escalate, the rest of the kids show up, reigniting their enthusiasm for the games. The Bakers’ triumphant resurgence leads to a surprising outcome: the Murtaughs equally match their score, resulting in a tie at the leaderboard's summit. To determine the victor, a thrilling canoe race is set, where contributions from each family member are crucial.
As the competition intensifies on the water, Nora's pregnancy takes an unexpected turn. The Murtaughs initially hesitate to offer assistance, fueled by Jimmy's pent-up resentment towards Tom, rooted in past feelings of inadequacy. However, Sarina’s gentle encouragement eventually pierces through Jimmy's defenses, prompting him to join forces with the Bakers to ensure Nora reaches the hospital safely. The scene transitions to Kate, Bud, and Lorraine, picked as baby Tom's godmother, accompanying Nora to the delivery room while Tom, Jimmy, and the rest of the kids wait anxiously in the hallway.
In a heartfelt moment of vulnerability, Tom reveals his fears of losing control as his children mature to Jimmy. He realizes that, no matter where life leads them, they remain forever bound by family ties, with their love grounding them through all challenges. The birth of baby Tom brings tears of joy, and Bud announces with pride that he and Nora have reclaimed their beloved lakeside cabin. As the family prepares for their imminent move to Houston, they cherish the remaining time of their vacation, rejoicing in the warmth of their renewed connections.
