It is certainly worth trying. A 13 y.o. clematis vine will have an impressively large root system so be prepared for some serious digging. Now is not an ideal time to attempt this move....can you wait until later in the season? And I would cut it back hard before removal.

I am sure she will let me wait. Do I cut it back hard now?

Be prepared for some serious digging is right, I dug a 20 year old Proteus last summer, July I think. It was an all day job for me, cut it right back and just concentrated on digging the rootball. I successfully dug and divided the rootball into three pieces. I potted them up watered them and put them in a shady spot until they showed signs of new growth. Left them in the pots for the summer, planted two back in the garden in the fall gave one away. I can see one or two flower buds forming on the newly planted pieces so it looks like they survived the massacre last summer. I started out thinking I was just going to dig and dispose but changed my mind once I got my teeth into it LOL. Waiting until later is a good idea if you can but if not with a bit of TLC it can work.

Thank you both so much. Love to see the pic.