Gibbs ensemble Monte Carlo simulations for salt-doped oligo(ethylene oxide) (OEO, M_w = 90–266 g/mol) solutions show that the presence of ions leads to significant increases in the cohesive energy density (Π_CED) and the enthalpy of vaporization for OEO chains but that compensation by entropic contributions leads to only small changes in the Gibbs free energy of transfer and vapor pressure. At the same relative ion concentration (r) and temperature, the Π_CED values of the salt-doped systems order as LiClO₄ > LiF > CsClO₄ ≈ CsF. Structural analysis indicates significant ion clustering in addition to coordination of cations by OEO chains. After accounting for ion clustering via the van’t Hoff factor, the solvent vapor pressures are well described by Raoult’s law. Experiments and simulations for a squalane/tetraethylene glycol dimethyl ether blend (x_W,OEO = 0.65) show that the addition of LiClO₄ does not significantly alter the miscibility gap below 0.95 T_CP,free, the critical temperature of the salt-free blend. However, the coexistence curve for the LiClO₄-doped system does not close with the usual power-law scaling at T > 0.95 T_CP,free as transfer of OEO chains to the squalane-rich phase leads to an increase in r in the OEO-rich phase, which, in turn, makes it a less hospitable environment for squalane.