I often freeze seeds after they are good and dry but I just do it to kill any possible bugs. I don't have room to actually store seeds in a fridge or freezer so I just leave each batch in there for a week or two.
I use pop bottles for large seeds like beans and corn, they seal really well, are far lighter than glass and don't break. Even just in thick zip lock bags I have not had problems with seeds going bad, even after several years of storage.
I have a small
underground seed vault for special and irreplaceable seeds. It's about three feet deep, seeds there are sealed in stainless steel canisters sealed with rubber o rings and wax or similarly in Pyrex test tubes with rubber stoppers.
I've found even small seeds like tomatoes and brassica have little loss of germination after five or more years. Something like onions or carrots are supposed to be less storable but I have never tried to keep them that long so I don't know.
Generally though I try to produce new seeds every year. I don't see a lot of need to worry over pushing the limits of how long a seed will stay good. Those in the seed vault are there more for insurance, no matter what, rather than long term storage. Two or three years is really more than plenty for me even though from what I've seen most stay good far longer just sealed up good in a dark cool place.