If you divorce and split the proceeds, you can claim the exclusion on your half of the gain if your ex-spouse meets the 5 year /2 year rule, even if you do not.
The partial exclusion rule for unforeseeable circumstances does not apply in this case. It can be used to to qualify for a partial exclusion if you owned less than 2 years, or lived in the home less than 2 of the past 5 years, but it doesn't go out longer than 5 years. (Look at worksheet 1, part B, step 1 in publication 523.) https://www.irs.gov/forms-pubs/about-publication-523
