Trying to book a room with points in London or Paris on points for 4 adults with 2 double or 2 queen beads. Plat eliteI member it possible to secure an upgrade before we go?

Trying to  make this work on points  without added expense.. Looking at La Defense , Champs Elysses in Paris  and  St Pancras and  County Hall in London.

I noticed River Gauche is available Cat 7  for lower points.  Does this location have a CL? Is it  close to the  subway station/ Trafalgar Sq.