Here's how big the LEGO 75313 UCS AT-AT is (size comparison) - Jay's Brick Blog
REVIEW: LEGO Star Wars UCS AT-AT with 6,785 Pieces! Set 75313 - YouTube
LEGO Star Wars at-at Walker 75313 Buildable Model - Collectible Set for Adults, Ultimate Build and Display Set, 9 Minifigures Including General Veers, Luke Skywalker, Snowtroopers and at-at Drivers, Building Sets - Amazon Canada