From what I have heard the police reacted very quickly on a large scale, in the absence of any evidence of a 3rd party involved despite extensive investigations. After 3 weeks there are still no clues at all, if the most likely event is falling into the river you don’t wait to do a risk assessment you search in case a life can be saved.
I don’t think “menopause” is a taboo word these days all women of that age have to cope with it, it is even a valid reason to have employment leave. In Nicolas case that or other things were causing mental health issues, leading to drink problems as well.
There was a weir downstream, below that the river is tidal and being swept quickly out to sea seems the most likely scenario. There is always hope, but with a police hunt of this scale it doesn’t seem likely