I would imagine that their gates would do as ours did. We went from 15,400 up to 30,000ish straight away when we moved.
They will then suffer the same fate as us - spending limited by new stadium debt - no new players, performances drop off, less investment in the team, relegation etc.
Why £160 to build a stadium? Get an identikit one like ours for much less. I know there's inflation but if you need to progress with a new stadium why insist on some fancy architects mad cap idea. Keep it simple - you kno wit's what you do best!!!