Very sorry to hear your news Simon. I had my Mk5 GTi taken in similar circumstances last June. I replaced it with a Mk5 GT TDi, which is very boring in comparison, but at least my wife can sleep at night......
Not sure if I would replace a GTI with a new one if someone broke into my house and stole it. It’s a really tuff and difficult decision.
I would be in two minds, i.e.
1) As a car / GTI enthusiast why the hell should I let thieves dictate what car I drive.

Or
2) As a family man I wouldn't want any harm to come to my family or put them under any more stress if thieves broke in again

We got burgled when we were away for the night about 5 years ago and my wife has never really settled in the house since. Now we are currently in the procecess of selling and buying a new house partly because of this.