NVIDIA may have released the RTX 3080 Ti as a 12 GB card, but it and AIBs were developing 20 GB cards. A leaked BIOS has confirmed a few aspects about the unreleased variant, including its ludicrous 450 W power limit.
https://www.notebookcheck.net/NVIDIA-GeForce-RTX-3080-Ti-Details-about-20-GB-VRAM-cards-revealed-by-BIOS-leak.560665.0.html