Thank you for all your input.
I think I've figured it out, in as much as I intend to make a decision nearer the time.
At the start of next week's session I'll fill R in on all this, and ask whether she can bear the Monday in mind.
Chances are I'll be in a better position to make the decision after the 'interim' session, anyway.
__________________
'Somewhere up above the great divide
Where the sky is wide, and the clouds are few
A man can see his way clear to the light
'You have all the grace you need for today, and today is all that matters.' - Steve Austin