I don't know much about "gardening in Texas" either, but I know clematis plants pretty well and they should do fine down there. no reason why they wouldn't that I can think of...? if you plan to transplant it soon, try to do it on a cool, cloudy day, if thats even possible in Texas this time of year...? or even better, wait for a time when its going to be cool and cloudy for a week or so. this will minimize stress on the plant and give you the best odds for a successful transplant. most clematis need at least part sun to flower well; if not full sun. but their roots need to be shaded and kept cool. a pot sitting in Texas style direct full sun will act like a small bake oven of sorts unless its shaded by something. other plants, a fence, or something, at which point the entire plant will droop and look terrible, no matter how much water you give it. also, do not use water as a cooling agent either. more likely the amount of water needed for "cooling" will be too much for the plant and will cause water related root problems. we have 6 clematis vines. our "Pink Champagne" (see pic), clematis is in a large pot about 20 inches across. its been in there for 4 years. doing very well! good luck
