I used to run an extension cord under the bed, laying the bed protector luggage pad over the top of it when I went to bed so I didn't trip over or get tangled in the cord if I got up in the night. Then simply unplug the cord from the socket in the morning (as you should do anyway rather than leaving it plugged in) and coil the cord under the bed and out of the way. Never needed more than one 15 foot cord which served well for hotels and cruise cabins. I am fortunate enough now to have a travel CPAP with a battery, so I don't need a cord anymore.
