Yes I would agree with Loch Lomond area. I once walked the west Highland Way
From Milngavie on the North side of Glasgow to Fort William around 100 miles
The route took us past the East bank of Loch Lomond over Conic and onto Inversnaid near Rob Roy's Cave
Great woodlands and fantastic scenery, The further North you go, the more wild the camping gets as terrain changes to a mountainous nature.
Agree with Woodstock, The weather is changable so be prepared for almost anything weather wise. The big plus is you should not have any trouble with the Midgy population in Feb
Just remember there is no such thing and bad weather, just bad clothes and have a great time.
Tell us all about it when you get back