An A3 sheet of paper is pretty much the minimum size for an Oval of T gauge track. Although the flex track can be bent to a tighter radius, the bogies on the mechanisms have limited movement, so won't go around sharper curves. I was involved with T gauge from the beginning, although I'm not active in the scale at present. The original advertising posters (see below) were on an A4 sheet in portrait orientation. This had, in actual size, a half double-track oval. So that two posters joined (with one upside down) gave a life-size illustration of the oval of track. So, unless you're happy with end to end running of around 20cm, or do some surgery to the mechanism/s (anything is possible). then you're going to need a fair bit more space for T gauge, despite its tiny size.