i never had any luck with nursing in bed either :?
i found that getting my kids on a routine made all the difference in the world. i also tried to provide cues to them whenever possible. during the day, i would talk to them, expose them to sunlight and whatnot. then, during night feeds i wouldn't make eye contact or turn on any lights or anything. (we had problems with confusing days & nights :wink: )
i was cluster feeding i think around 5pm, 7pm, and 9pm around 3 months old , and that helped carry them farther at night.
dunno what to tell you about sleeping on the sofa... maybe set a soft timer to remind you to put he rback to bed???