cold temps/water lines

So having all this free time in the days of social isolation, last Friday I drained all the rv antifreeze out of my lines and flushed them good and got the camper ready for the summer...if we get a camping season. Put water in the fresh tank and ran it into the lines and we even had a meal in the camper last weekend. Anyway, now I see a few days coming up with overnight temps in the 20's and daytime temps in the 30's. Thinking of just draining all the lines and blowing them out with air and emptying the fresh water tank. Or, would just leaving the lines pressurized with the pump on be safe? Suggestions?