You should have enough time. There is a 8:20PM Nozomi 263 from Tokyo to ShinOsaka arriving around 11PM. There is a 8:30PM Nozomi 127 also.
You can catch them at Shinagawa about 6-7 minutes after Tokyo departure. Shinagawa is a bit easier transferring from NEX or NEX+Yokotsuka line.
Just remember to pick up an egiben at Tokyo or Shinagawa for dinner on the train.