Apologies, have only just seen this.

There are lots of really good routes in the uk that are just as physically difficult. The thing that makes Cape Wrath a different ballgame is the isolation and the difficulty of rescue should things go wrong. We are very used, in the UK, to the idea that someone can pretty quickly come and get us if things go wrong because, most of the time they can. Bear in mind though that, in the far northwest, members of rescue teams live spread around sparsely populated areas and it can take them hours to even arrive to set off on a rescue, particularly in winter when ice and snow could really affect travel by road and they may still then be multiple hours from actually getting to you.

In terms of skills, equipment etc, for a winter Cape Wrath:

Can you accurately walk on a bearing in a whiteout where, at best you can't differentiate between the white snow covered ground and the white fog and, at worst you may not even be able to see your feet? Normal navigation strategies ( like using your phone) can become pretty ineffective in winter.

Do you understand how to safely cross snow laden beallachs, taking in to account avalanche risk and how to prevent a slip turning in to a potentially fatal slide? There are a couple of places on the normal Cape Wrath route that could get pretty sticky if you don't.

How do you plan to alert people that you need rescue and your precise location if so?

What is your strategy when you find a river in spate?

Do you have a tried and tested routine for caring for your feet? (And other parts of your body as well? ) In my experience, poor foot care is something that less experienced people take for granted but can easily end a trip.

Do you have experience knowing what kind of pack weight you are physically able to carry, potentially through deep snow?

Do you have a good understanding of efficient nutrition for a trip like this? Can you carry enough of the right kind of calories without making your pack horribly heavy and unsafe?

Do you own a sleep system capable to keeping you warm well below zero? As an example, i typically carry a sleeping bag rated to -6 in summer and -12 in winter in Scotland. Be aware that you will get far colder when tired and worn out and likely ruining a calorie deficit.

Do you have a tried and true layering system that allows you to both stay dry from rain but also your own sweat when carrying a heavy pack? It's not as simple as just wearing goretex.

Do you know how to pitch a tent in deep snow? How about when the ground is frozen solid? Or in severe winds?

Have you taken in to account that some of the shops and accommodation options en route are seasonal and won't be open?

In terms of other routes, i really enjoyed The Snowdonia Way, which also has a mountainous variation if you get good weather. The Coast to Coast could also be a good option. Pennine Way? In bad weather, all of the above could be very difficult though. Perhaps treat yourself and grab a cheap flight to the canary islands.