Southwark have had fortnightly pickups for a few years. I think the Garden/food waste (brown bin) is still weekly. My neighbours and I share a brown bin so don't always notice.

It hasn't really been a problem. Yes, sometimes they fill up if you've had a spring clean but didn't notice them being particularly whiffy over summers. My Mum's council is moving to three-weekly collections of general waste from fortnightly.

I think fortnightly have become the norm in recent years.