Waterproof case that seats behind the rear seat in a 2020 TI

Hi all, I recently purchased a 2020 TI and I'm outfitting it for a long distance trip. I'm trying to find a fully waterproof box (ex. pelican case) that will fit behind the rear seat in the inset without impeding the rear hatch. Unfortunately everything I have seen just doesn't have the height/depth to provide ample storage and wisely utilize the space. From my measurements something 16.5 in long and under 13.5 in wide base would fit, but height would need to be about 12-16 to really meet my needs. Im using the the box to store camera equipment, sensitive gear, and a drone as well as to hold my lithium batteries. I have seen a yeti box that would have sufficed (but on the very heavy side) but was about $300. If anyone can suggest a manufacturer or brand to check out that might meet my needs please let me know.

Thanks!

Noah

You might have more luck with a softside bag from EarthPak. I have a 70-liter dry bag and it works great. Comes in smaller sizes too and might conform better to your space requirements.