Is the continuous smell of urine in clothes—given the difficulty of changing or purifying them, especially in winter, or fear of sensitivity—sufficient evidence to consider a person as suffering from سلس (urinary incontinence) and to pray in these clothes?

You are afflicted with waswasah (whispers/obsessive thoughts). Therefore, we advise you to ignore them, turn away from them, and pay no attention to any of them. Do not judge that urine has exited except with absolute certainty. As for doubt, do not give any attention to these doubts, and pray normally.