Contemporary images of tents are numerous in the later fifteenth century. Its clear that noblemen's tents came in various shapes - round, wedge, wall being the most common - usually mixed within a typical encampment setting.
To create a larger tent, I've used an anachronistic reference, deriving from English Tudor images of the 1520s, which show designs for substantial tents for the Field of the Cloth of Gold (taken from original images now lost). These appear to show conjoined round and wall tents, making either separate rooms or larger covered areas that you can move freely within. I've yet to find this joining of two round tents in images contemporary to the 1470s.