If your propellant depot is at the edge of Earth's gravity well, you have the option of refueling but you'll need more propellant for the same trip using chemical because you can't use the Oberth effect.
IIRC, anything in the temperature range of LO2 can be kept liquid with radiative cooling in earth orbit (which means an insulated tank won't have any significant loss, and the insulation's importance will come in depending on the altitude of the depot (it gets easier the higher you are, as deep space is a larger and larger fraction of the heat equation, and the universe's background temperature is 4 degrees K...).
LH2 is just a PITA; we'd never use it if the ISP wasn't so high...