Severn Bridge route advice needed

We have cycle tours regularly crossing the bridge into Wales and we’re trying to find a way of anticipating which side of the bridge will be closed in advance. They closed the south path last week and it caused chaos amongst the group. We were using our usual route along New Passage Road and that closure started the confusion, which was then compounded by them needing to find a way over to the north path (steep steps over a footbridge…)

We’re thinking of rerouting to approach from Olverston, but I’m thinking you’d need to know which side of the bridge would be open before you get to the big roundabout? (Turn left and through Aust if you have to use the South side). I can’t find an info source that would let us inform our riders in advance. Avoiding the A403 would be a massive bonus.

Any local knowledge welcome!