at 10C (50F) you follow an isotherm at about 650psi (horizontal line labeled 50F where you get liquid-gas saturation). At -10C (14F) you get an isotherm at 400psi. 38% pressure drop across the temperatures you specified. Unless you're shooting from a regulated supply of CO2, you're going to see significant performance variation across your specified temp range.
Don't even bother with propane.
Swing from 78psi to 38psi. The higher pressure is already borderline acceptable (about the same as HFC134a at 20C).