You'd get better answers if you were specific about the film. I've found Sensia 100 holds up great and I've never had a bad batch going as expired as 1996. Provia is okay but not quite as stable. Velvia has been the least stable for me unless it's been frozen. Astia was pretty darn good. Actual "Fujichrome 100D" from around 1995 was unusable, couldn't render black as anything darker than a light green.
I wouldn't say that slide film degrades faster/worse than color negative, I've actually found it to retain film speed a little better on average. And I've seen that Fuji does tend to hold up better than Kodak as a general rule. But not always.
I think it's more that with slide, people are looking for perfect unadjusted results. But if you treat slide as an adjustable medium like color negative, you can pull out usable pictures.
For example, this slide immediately below is almost completely pink-purple to your eye in real life, and you can't see any deep blacks on it. But adjusted, you get a pretty full range of color (though a bright vignette effect on the edges). It's 2004 expired Kodak Ektachrome EPN 100, unknown storage conditions but probably somewhat heat exposed. The film speed dropped from 100 to around 40.
Now, here is the 1996 expired Sensia 100. It has a purple cast which is easily removed, but for this shot I found it added something and I kept most of it in. The film speed on this didn't drop at all, you can still shoot it at box. And I don't think it was frozen.
Do a few tests of the first roll at +1/3 and some at +1 1/3 too. That should be enough to inform how you can use the rest of the batch.