The Epson V700 and V750 scanners can scan 8x10 negatives. I have the V700 and have scanned 8x10 negatives, both film and glass plates, with good results.
If you are in the market for a very good scanner, the V700 is a great choice.
If not, try to find someone with a V700 to scan it for you.
Or, for only one negative, perhaps you could rig up some kind of light table and then take a picture of the negative on the light table. It would then be easy to reverse the image to a positive in most any photo editing program.