I know loads of places miles from houses that would be fine, maybe a bit rough for some of the city slickers though
A lot of spots on the A87 road to Skye
Some on the A830 road to Mallaig
One or 2 on the A82 but it can get busy
Might be one or two on the A835 road to Ullapool
There's a big decent spot on the B9176 about 10miles north of Alness
All of these you'd be fine just turning up at but it's wild camping so no toilets etc, some spots have a burn or loch near by
I also know a local landowner with I think 70acres which he lets me and my mate etc camp on but there is no vehicle access to the decent spots. I was there over the weekend, about 15min walk carrying my gear.
Also I will again be at the tartan heart festival this year if anyone wants to join me