Keep in mind that baby puke on fabric seats never really comes out...

Personally, I would choose a second hand (say 1-3yo) Octavia. One of the guys I work with has the latest gen one, about 1yo, and it really does look nice. And it seems big and practical as any small family could need.

Also, given the bad press for VW group currently, you might find that prices keep dropping - on both new and used.

Alternatively just keep the GTI and buy a cheap Camry. You'll hate driving it but never have to worry about the condition of the interior... or exterior.. or anything really!