An easy one, on estate tracks, is go in at Ardoss just up from Dingwall, through Glencalvie etc and come out on the dam side of Loch Glascarnoch on the DIngwall-Ullapool road. It’s possible to continue back to Dingwall almost all offroad from there. I’ve done it – some nice scenery, and a good one day break in ride for early summer.
If you want to do it at an easy pace, I’m up for it because I’m intending doing it in the next few weeks (I ride a rigid singlespeed).
Also the Corrieyairack is a relatively easy ride, you just need to be prepared for weather. I prefer doing it from the A9 side because the views down to Loch Ness are better IMO.
From the sound of what you have said, you may be interested in the Rough Stuff Fellowship type of riding, ie ride to get places rather than for thrills.