What is the best time to visit Great Smoky Mountains National Park in Tennessee and North Carolina, considering factors such as weather conditions, crowd levels, accessibility to popular attractions, and the types of activities available throughout the year? Could you provide a comprehensive guide on how the park’s seasons (spring, summer, fall, and winter) influence the visitor experience, including when to visit for wildflower blooms, wildlife viewing, fall foliage, and scenic drives? Additionally, how does the park’s elevation and microclimates affect different areas at different times of the year, and what are the best months for hiking, photography, and enjoying the park’s natural beauty while avoiding the largest crowds? What are some tips for navigating seasonal road closures, trail accessibility, and making the most of each season’s unique offerings?