Winter or 4 season tents are generally designed to be able to withstand snowfall IIRC, and as have been mentioned already some come with snow valances that you bury in the snow – basically an extra long flysheet. The downside is condensation as it restricts airflow. I’ve used them in the arctic where you are pitching on several feet of snow, in Scotland that is less likely of course
IMO the main criteria for Scotland is stability and strength in high winds, and general weatherproofing. I have a Terra Nova Voyager that is rated as 3 season as it can’t really take heavy snow on its flattish roof. However it is extremely stable in high winds, and otherwise a good design for the UK with low cut fly and bathtub groundsheet. It has managed snow fall on the roof, just not loads of it. In reality, snow on scottish hills is generally going sideways and not vertically, so the big build up on the roof of your tent won’t happen like it does in the Patagonia catalogue.
So a good solid 3 season tent will probably suffice in the real world and probably be quite a bit lighter. Personally i’d be looking at geodesics as they will stand on their own and providing you are in it, they (probably) won’t blow away!! I have a Quasar too, and while it’s going to stay standing after all your clothes have been ripped from your shivering body, it is heavy.
The Laser wouldn’t be my first choice for a winter tent, you could make it work with a sheltered pitch but it is gonna get battered in a strong wind! Lots of fairly flappy panels to catch the wind and drive you mad. Once the pegs rip out it will be misery.
There are a few MSR tents that look pretty good and seem to have good customer support. They do tend to have quite high cut flysheets though, something to think about in blowy weather. On the plus side they come in at good weights
Ultralightoutdoorgear website is a good site to peruse lots of tents and compare weights and staff reviews, well worth a look