I knew it could get out of control, but turns out knowing is not experiencing it. It's just nearly 2 months since I got my first fdm printer and this is the result. 1 roll is finished 12 stacked to go.
I got a clear plastic bin from Lowes and a huge reusable desiccant bag from Tractor Supply. They keep my filament perfectly dry. The bag is like 2 years old and I've never had to cook it to dry it out.
A pretty decent and cheap choice for containers are Ikea Samla boxes. You "just" need some weatherstrip from the hardware store to create a decent seal on the lid. Oh, and don't bother with getting Ikeas lid clips, they're crap compared to the printable "ultimate Samla clip".
I have the 45l Samla box, it has space for about 10 spools of filament. Printed some infill grid as a "spacer" and just dumped 1kg of desiccant in, constantly keeps the RH below 20% and only has to be recharged 1-2 times/year.
They each hold about 8-10 spools comfortably, and seem to make an excellent seal. Probably a little costlier than DIY-ing IKEA totes, but convenient if you just need 1 or 2.