Very timely for me to read this post!
My plan is that I'm going to continue in schoool at a manageable pace for as long as I can. With my PhD I will be able to continue securing less physical positions, more opportunities and better money. My thought is even if I eventually only work one day a week I will probably make more money than the average disability income.
It is a gamble but I figure I will have plenty of time to relax when MS finally takes my ability to work and no way do I want to look back in 5 years and still be slogging along without having attempted it.