Can you have herpes all over your body?

Yes, but rarely. There are several different types of herpes virus. The chicken pox virus (varicella) is a type of herpes virus which does cause blisters to form in an "all over" (ie. Disseminated) pattern. The herpes virus which causes oral sores or genital ulcers (hsv) would very rarely cause a "disseminated" infection. This is unlikely to happen unless a person has an extremely weak immune system (ie. Hiv/aids).
Herpes All Over. Yes, you can have herpes all over, but only in rare situations where you have a significant skin barrier impairment allowing it to spread readily or you are very immunosuppressed and typically you would be very sick if it were all over. If you any kind of all over skin rash or condition, you should see your dermatologist immediately.