Scotland in late Dec/Early Jan

The biggest disadvantage of travel during the period you gave isn't the wintry cold or rain, it's the lack of daytime hours. Scotland is pretty high up, and my experience with living there for two years is that you'll only have six hours or so of daylight. Factor in the inclimate weather, and your options are going to be significantly reduced.

Of course, on the upside, you'll be there during New Year's and Hogmanay! There's a lot to be said for that!

You may want to focus on indoor attractions. The major museums are spacious (I'm thinking of the National Museum in Edinburgh, for example) so you can walk around without your overcoat and feel unrestricted.

Check for hours of opening of various attractions. Some may close altogether in winter, and many have shorter winter hours than summer.

It depends where in Scotland you are travelling, but if, say at altitude, you may get significantly more than "slight" snow. Picturesque, but the country grinds to a halt with 2 inches of snow. If using trains, the network can be closed in parts between Christmas and New Year, when track maintenance is undertaken.

Many of the historic homes and gardens will be closed for the winter. Everything closes for Hogmanay.

There are parts of the UK that I would prefer to visit at this time of year - all much further south. Heading further south in Europe is even more appealing!

Good bits of info. Just what I was looking for.

Thanks guys!