Went to Cream last year solo through Festaff. Signed up last minute so only had the option of bar staff, if I was to volunteer again I'd pick bar because you don't have to wake up early. There were quite a few people who came solo and everyone was super friendly. We had our own area in the staff camp, could come and go between the arena and camp site and had access to the other campsites It's really chilled out, the staff are lovely and last shift is Saturday so you can enjoy the best night. You get hot access to hot showers and provided with food on shift.
Had a great time and will be going again this year but as a paying customer. Going Bronze. Will be going solo but know of a few people also solo going bronze, standard etc.