Remus hadn't owned dress robes since the handmade ones his mother had sewn for him while he was at school. Nor did dress robes fall into the same category as wands as things he was willing to accept funds from Harry or Ted for. Transfiguration would serve him as well as anything and he could tailor them to fit his specifications without needing to stand for a tailor's measurements.
Trying not to reference classic American novels in his mind, he opted to convert the curtains in his room to a set of close-fitting dark chocolate brown robes with a high open neckline and no sleeves, to allow the cream-colored shirtsleeves he wore underneath to show through. Brown dress slacks were completely hidden by the robes, which were closed with simple fasteners to facilitate easy removal if he need to be unencumbered.
Not that he wanted to think about what it said of his mental state that he was thinking escape strategy for a dinner party!
When he arrived at Malfoy Manor with James, he almost suggested they turn and leave when it was made clear they would have to turn over their wands. Despite the delay in replacing his old one, Remus was definitely not comfortable with the idea of turning his wand over to anyone. There was more than one reason he didn't go to the Ministry offices, after all.
But, he figured Sirius would take a piece out of his hide if he didn't show up or if he talked James out of making an appearance. And, while Remus had been surprised that James wanted to be out amoung people so soon, he was the last person who'd be willing to try to keep James and Sirius apart after all that had happened!
In any case, if he was lucky Ted might be there and Remus could finally introduce his friends to his son.
The sheer number of people in attendance was somewhat overwhelming, between his own more solitary tendencies and the overload of sounds and scents to his senses. He supposed it was only a matter of time before he lost track of James in all this and found himself wandering through the Great Hall on his own, passing on offered drinks/food by habit and remembering why he'd usually stayed only the briefest amount of time before escaping to the library during House parties in the common room during their school days.
Of course, there hadn't really been much to throw a party for in the years since.