I did a bike and walk. I parked up near the Cluanie Inn, cycled down to Malagan Bridge, and then started up the track to Forcan Ridge, before cutting up left on a more direct route.
My report on the walk might help.
https://www.walkhighlands.co.uk/Forum/viewtopic.php?f=9&t=42804As far as timing goes, the walk took a couple of hours longer than expected because I got an attack of lateral tibial band syndrome just before I set off back down to Cluanie, that made it excruciatingly painful to walk downhill. So if you're reasonably fit, you could probably do it a fair bit quicker than I did.
As far as replenishing lost minerals when you get back is concerned, the Cluanie Inn sold good beer when I was there, but I've visited since the refurb, and it no longer does.
It's an absolutely fabulous walk, with brilliant views from beginning to end. You will certainly enjoy it if you get quarter way decent weather.