Hi Dal37.
Living apart will put strain on any marriage, so its not an easy or ideal situation you are in regardless of your wife's health.

The dividing line between Bipolar II and Bipolar I in terms of mania is somewhat arbitrary, and is just a matter of degree.
People with Bipolar Disorder tend to experience emotions very intensely.
In mania, we tend to find many things fascinating, the ordinary suddenly reveals gems and pleasures previously unnoticed, and people we would normally have passed by become highly attractive. Our bodies surge with energy and excitement and fleeting moral dilemmas give way to dizzy and impulsive attractions. Our judgement becomes impaired.
We may drive recklessly or get intimately involved with people we normally would not.
If we are not able to keep our mania in check, it can lead us to do serious damage to ourselves and those around us.

I have been very fortunate to have a wife who I can count on to help me if I miss my warning signs.

While you are not with your wife she probably needs a good friend she is in contact with on a daily basis, whom she can count on to be honest about her signs and behaviour, and get medical help immediately. (When we are manic, often we resist help or don't seek it on our own). She will need help just as readily when she hits the depths of depression, which is probably the more dangerous part of bipolar II.