I have to leave the bus stored inside (plugged in) for up to two months in the winter without takeing it outside and getting the engine up to operating temperature.

Although I am unable to drive it during this time I could have someone start it once a week and get the oil pressure up and then shut down.

Would it be better to start the coach up every week for a couple of minutes and then shut down without getting the engine to operating temperature or would that be more harm than waiting a couple of months to drive it?