What triggered this was IanF's idea of a list of long distance routes, gpx's.
One of my early Scottish explorations was Oban to Aberdeen - 200 miles, done in 1997, end of October, well before all the fancy rackless gear we have now, and NO gpx, just copies of bits of maps.
Started Sunday, arrived at the sea in Aberdeen Thursday afternoon.
Took plenty pictures with my camera to discover later there was no film in it

Blessed with dry cold weather.
With some modifications this could be a really great trip, with some good riding, and a bit of H-A-B second to none (only about 3 miles but certainly a lot of bang for your buck)
The last 40 miles were on a (quiet) road though... better options via Mount Keen, but I've not been there so couldn't vouch for anything...
The section from Gorton Bothy to Rannoch Forest (probably less than 3 miles) took two and a half hours... ( but quite a few on here would relish that no doubt

I would have to create a gpx via Memory Map
Thinking about it (I'm not riding until a week today, resting a persistent shoulder injury) there could be quite a quality route there:
Oban to Taynuilt - 12 miles very quiet back road
Then over the River Awe on a weird narrow suspension bridge, and a good rideable undulating track on the east side of Loch Etive, as far as Glen Kinglass
Good track (mainly, but a bit of bog later) to Forest Lodge (on WHWay)
And more good track to join the A82
I went down the road for half a mile then took the track eastwards 6 miles to Gorton Bothy
Then the bad bit, really bad...

Over the deer fence (locked !) and into Rannoch Forest: some technical single track at first before joining a good track.
I came out at Bridge of Gaur, then took the minor road on the south side of Loch Rannoch , as far as Kinloch Rannoch- but a good variation would be to take the HT550 route until it heads south, then use the forest tracks to get nearer to Kinloch Rannoch.
I used the B846 to the minor road just before Tummel Bridge, where I turned left then after a kilometre took the forest track through Tummel Forest all the way to Edintian.
From there it was just over the moor but still riding until Tomanraid, then a 'sort of' track until the huge descent (rideable...

From there up Glen Tilt and the normal way to Braemar.
Road to Invercauld Bridge then good tracks via Balmoral, to swing south on a good track to Glen Muick.
Track down Glen Muick to emerge at Ballater.
I took the quieter road from there to Aberdeen, but I'm sure there are better options by heading towards Mount Keen, and maybe emerging at Stonehaven
I can concoct a gpx if it's worth it.
What we need though is some good off-road from Glen Muick, to perhaps Stonehaven.
What matters most, at least to me, is a great off-road adventure with good riding and technical bits if possible, and... not too much H-A-B, in good country.
If someone can provide a gpx of routes from Glen Muick I'll provide the earlier part...
??