I did Guildford Half (local race) and then Windsor Half the next weekend. In Guildford I took it easy and had fun talking to people and ran 2h7m38s. In Windsor, a hillier course, I concentrated, didn't talk to anyone, put in a real effort and ran in 2h7m19s. So it is possible to do two in a row. Maybe if you worked hard at Windsor, you just want to try to enjoy this other race?
Go for it!