I'll probably get shot by some here for saying this but I'll go ahead and say it. If at all possible, hold off on getting a MS diagnosis until your insurance issues are worked out. Take care of all of your insurance issues including health, life, and disability. Once he gets that label, it will be a lifetime of issues. There are certain rules about pre-existing conditions, group coverage and open enrollment periods that you may be able to work around if he does get the diagnosis, but they are complicated and it's best to not deal with the headache.
Here's where I'll probably anger some people. It probably won't make a difference in the long run if he's diagnosed now versus 6 months from now. The MS drugs help but they're not so great that it's going to make a difference in the long run if he starts them now versus a few months from now. I personally think it's best to wait and make sure that once he gets answers, you and he will have the means to get the appropriate treatment.
So, why would you think you'd get shot or anger some people, for giving very sound, rational advice?? Indeed, it is important to make sure, if at all possible, that your financial affairs -- health insurance, all that, are in order, if there is any question about a diagnosis. And indeed, 6 months isn't all that long in the grand scheme of things, if it is indeed MS, and a long-term, life-long chronic condition.
Lorgirl, I've been reading your posts, and here's my -- again, uninformed not-a-doctor opinion: Sounds like your husband likes his job, he's getting a promotion. I'd say go ahead and move forward with that, sign up for the health insurance with his employment, and when you re-locate there, look for employment yourself (or start looking now; six months isn't a long time to be searching, these days..) You said you're job might not be the best but has good benefits...you might find something you like better and with good benefits, too.
You can't plan ahead for every contingency in life. Sometimes stuff happens. All you can do is make sound decisions, a few at a time, and move forward. Sounds to me like the move and promotion, within a company he's worked for, for a long time, are good decisions. If it DOES turn out to be MS, he's got some support at his place of employment, where he's worked, they know him, they know what he's capable of, and they might make some allowances.