The whole point of Brexit is self determination and democracy. If a majority of the Scottish people no longer wish to be part of the union then so be it. Regardless of the EU referendum the SNP will have their second referendum sooner or later anyway.A great deal of uncertainty though. As you say, Wales may follow Scotland in time.
Will it still be called the United Kingdom if Scotland leaves?
Many of those advocating Brexit, British exit, have a notion of Britain becoming great again with independence but how much of Britain will be left? Maybe it should just be termed Exit.