Very few engineering schools let themselves get to such an extreme gender imbalance, but if you really were picking between an 80/20 split and a liberal arts school, I'm highly confident that you are much better off for having picked the liberal arts school.
Is it? I see evidence of quite a few groups that are all-female and want to stay that way.
http://tripletsdad.blogspot.com/2008/10/at-home-dad-banned-f...
More women will get into engineering, because of exposure, high salaries, and employer demand.
Likewise, Male engineers will actually meet women.
At Pitt, where I went for undergrad, the count for Computer Engineers/Electrical Engineers was something like 525. Only 38 were women.
On the other hand, if you were well adjusted, you had no problem meeting women outside the engineering building.