The article titled "ULTIMATE Winter Sports CHALLENGES" is a full episode of the show "Mack the Track Hacker" featuring Hot Wheels. The episode revolves around various winter sports challenges. It showcases Mack, the main character, engaging in different activities related to winter sports.

The main idea of the episode is to present a series of thrilling challenges that are specifically designed for the winter season. Some of the exciting activities shown in the episode include skiing, snowboarding, snowball fights, and ice hockey. Mack, along with his friends, attempts each challenge with enthusiasm and skill, creating an entertaining and action-packed show.