Alex, you do have quite a quandry there on your hands. I would be tempted to try and move it even though it will set the plant back when you do so. It make take it a year or two to get back to its current state. I wouldn't worry about having to dig up the lawn and any residual nitrogen in the soil since the grass will more than likely have used up any previously applied fertilizer. Addition of more topsoil would help dilute any that is left. If you weren't having to add the foot of soil all at once to the existing site you could probably keep the clematis where it is. We are constantly telling people that clematis should be planted deeper in the ground than they are in their original pots, but one foot of soil would be an awful lot to add at once over the crown of the plant. If you could place a bottomless drum around the plant using say a cardboard form that is used to pour concrete or something similar, you could gradually add soil into the form over the course of a year or more as the clematis grows and that could possibly work. It would be definitely more work than just moving it but only you can decide which you are willing to try to keep it in its current location. Let us know what you decide and how it works out.

I agree with Janet and as she well knows I have beating this drum for several years now. The old adage of heads in the sun and feet in the shade is an old wives tale. Moisture is what is required and that typically occurs when the roots are shaded since it slows down the evaporation of the water in the soil and the consistent moisture is the critical element, along with appropriate fertilization. For what it is worth, I have potted up countless numbers of clematis into one gallon sized pots and left them in the sun where they get morning sun thru midafternoon sun and they have been fine. One definite advantage of sinking the pots in the ground is that you won't have to water the pots as much since the soil will act as an insulator to the desication of moisture from the potting mix. Just make sure that the surrounding soil drains well or your pots could hold too much moisture and cause root rot.

The powder room is very small and is sandwiched between the kitchen and living room. We cannot put it in the dining room nor the family room and don't want it to go in the kitchen. We considered an addition over the garage and that was pricey and would raise property taxes. I would love to have it in a master closet, but we have two small ones in there that barely fit our clothes. I even considered ripping out our huge corner tub in the master bath and putting the washer and dryer in there. The contractor explained that would involve a total remodel of that room and would be very expensive. I knew when we bought this house that this would be my one issue. I may just have to live with it :)

What's it growing in now? If moving from one pot to a larger one, sure, do it now before it gets any further along and difficult to work with. If in the ground, then I would question the need to put it in a container. Much easier to deal with the plant in the ground without all the associated details of container culture.