It looks like getting in shape and having more opportunities to train are the things that are high on your reasons for training. I'd go with the new school and leave your JKD school. There is a problem why he is having trouble keeping his school staffed and open. Since you can only afford one school, make it the one that will give you the best value. People really do change schools for a variety of good reasons. The teacher deserves your loyalty not because of his lineage, but because he offers you the best training opportunities. That is my 2 cents. As with all advice, take what you can use and leave the rest.
The older I get, the better I was!