Old Suit (15 to 20 years old)

I just dug deeply into my closet, and came across an old suit which has held-up well...I think. The fibers are showing minimal wear and tear. I had bought this at Harry Rosen for close to $1,000. Aside from the fact that it desperately needs a dry-clean, should I keep it or donate it? Is it out of style? I ask because I will be attending a funeral in about two weeks time.