Are 12 hours of poor sleep better than 8 hours of poor sleep?

I have chronic sleep deprivation (many years) due to a neurologic disorder which includes PLMD and reflux disorder as symptoms. Requip has not been effective in calming my legs. And Provigil is no longer helpful in keeping me alert. I have difficulty getting to sleep from the reflux/congestion, then I generally sleep about 8 hours with a several interruptions from spasms and cramps. Sleep tests showed nearly 1 movement per minute. As things stand, I am going crazy because I am in a permanent mental haze. At my best, it is like I've been awakened at 3AM with an urgent request. I can function and deal with something for 20 minutes before my brain gives out. I am trying to decide if it would make sense to simply sleep more hours, nap in the afternoon, stay in bed for a week, etc. Can I catch up some by sleeping more (even poorly), so that I feel better when awake? I do not seem to be able to improve the quality of my sleep. I am also very susceptible to medications with sedative effects; so I have to minimize use of such drugs. Caffeine seems to be of little help in keeping me alert.