I suggest ignoring Seth's suggestion made above to use MapQuest in this area, it'll surely cause you problems and am curious why he'd make such an uninformed suggestion for this area.
NC State Road 80 from the Blue Ridge Parkway down to Mountain Stream is steep and twisty with several hairpin curves. You might be wise to avoid it with the motorhome and toad unless you have a good comfort level with mountain driving.
I have driven it with my fifth wheel and had no problems whatsoever but I drive these mountain roads all the time and am comfortable with it. If you do choose that route, keep the rig in it's lowest gear and don't let your speed build up.... hold it down to about 15mph and you should be fine.
Although not as curvy as NC 80, you might also want to avoid NC 226 south from the Parkway, it has steep grades of 14% and is locally known as a dangerous stretch of road. A trucker was killed on it last summer, brakes gave out and he plunged 300' over a cliff. To get to Mountain Stream from the Parkway you might be better off to get off at US 221 and take it to US 70, then pick up NC 80 off of US 70 and go north to Mountain Stream. NC 80 isn't bad on that stretch..... the problem is north of Mountain Stream.
To get to Hungry Mother and also to see some scenic mountain views without the risk of treacherous driving I'll suggest taking I-40 west to Asheville then pick up I-26 and take it up to I-81 north of Johnson City, TN. You'll still be going over the spine of the mountains on I-26 but that part of the highway is new and they've built it so the steepest grade is only about 6%.
When you go by Unicoi, TN on I-26 you'll only be 13 miles from where we live.