I have a dvd called Dahn Yoga for MS. It contains a lot of energy exercises plus some more traditional yoga postures, all easy to do with variations for sitting. I feel invigorated after doing the dvd and find it easier to walk. The whole Dvd is about 50 mins, but can be done in eections of about 15 mins. I also have a dvd Yoga for MS and similar conditions, I haven't tried it yet, the exercises are more for strengthening the legs from the looks of it. Lastly, not yoga, but Shibashi - an easy entry into tai chi qi gong. I'm taking a live class for seniors, I'm the only one under 65 there, and have a chair next to me. It looks deceptively easy but works the whole body quite nicely. I have just started and can follow the class for about 30 mins standing up, then I just sit down and do the movements from there. You can find videis of it on youtube - some are with leaning down, but my teacher does not teach it that way. I love the flowing mocements and that it helps to improve my balance. The whole sequence done at home takes about 30 mins and has a meditative aspect.
I love yoga and tai chi, I did not really exercise before my diagnosis. Unfortunately I believed a physio from the MS society for a vit who told me that yoga and tai chi would be useless for me; he said I should go to the gym and do cardio & strength training. I can only assume he hasn't tried either of those modalities and am happy with my choices
Good luck for you on your journey!