Unless you both really want to go to Scotland and don't mind running the gauntlet of what could be appalling weather for a week at that time of year then go for it.
Personally 'd get the Eurostar to Paris/Brugge for a week it won't cost anymore than Scotland but your less likely to spend a week getting rained on and freezing cold.
Before the nationalists get me I'm not anti Scotland I just wouldn't recomend it at that time of year for a casual visit it's much nicer in the highlands for the average person in the summer!
True to a certain extent, the weather has been up and down. Some nice clear bright day, and relatively warm. We're supposed to be getting more snow again.
It would depend on when it is, if it was forecast torrential rain then yes I'd rethink it myself. Could be nice, snow covered or sodden.