Liquid mixtures of simple solvents can form nanosized clusters, even relatively far away from their critical point. We propose to revisit the monophasic region of these seemingly simple mixtures, as the mesoscale inhomogeneities they exhibit can explain unusual chemical (re)activity, solubilisation properties etc. We focus on the case of ternary mixtures where two largely immiscible fluids are homogenised with the addition of a solvotrope. We will determine the location of two important pseudo-phase boundaries that we identify as the Lifshitz line and the Widom line, in two similar ternary mixtures: water/ethanol/1-octanol and water/ethanol/2-ethyl-1-hexanol. The later is an isomer of 1-octanol, with a greater propensity for self-aggregation in the form of rings rather than chains, making it far more difficult to pack. We will map the phase diagrams by in situ auto-dilution, and will complete our study with temperature scans to characterize the critical exponents of these systems.