You can certainly try to grow the climbing hydrangeas in a large pot - and for a number of years I am sure it would work. This woody vine does need room so after it becomes root bound in the pot the top growth will suffer. This vine also attaches to a support with suction cup-like roots so it will be hard to remove should you ever need to transplant to a larger pot. I would like to suggest a more compact clematis instead. Clematis will not destroy the wooden wall or support structure, but as your two plants would give as a gift, just plant and enjoy for as long as they can survive in pots and you can contain their growing enthusiasm. Keep growing, Marianne Binetti