Freeze, don't freeze, something else?

Always planned on freezing my seeds and read both pro's and con's.
Anybody freezing seeds?

I save most seeds, but carrot and onion I purchase. Looks like one of my favorite long term storage onions is currently unavailable. Hopefully not a permanent thing.
Fortunately I have a lot of older seeds, and planted some test seeds today to get a feel for germination rate, if any. Due to their age and an assumption they won't be available next year (don't know)
I want to freeze or do something to assure their viability for future gardens should they germinate.

Any suggestions?