Since you have a specific thing you'll need to plug in right by the bed, I'd bring an extension cord and a power strip!
Chances are, the plug-in by the bed might be hard to reach (outlets are often hidden behind hard-to-move things in hotel rooms). Plus, you'd have to unplug something (like the bedside lamp or clock) to plug in the CPAP machine.
Power strips are great - we have four women in our group, and we all have cell phones to charge up at night. Besides that, one of us has a laptop, and I have to charge my digital camera battery in an outlet - there never seem to be enough outlets that are easy to reach, especially when you realize you have to unplug something (like a lamp) to plug your items in!