I live in Welwyn Garden City and there is a great shortage of 2-bed accommodation in the area and rents are expensive including Potters Bar, St. Albans, Harpenden, Hitchin and Stevenage.
We found this when my daughter needed to move from Leicester to be closer to us. She ended up near Biggleswade as it was the only area that she could afford, unless you go to somewhere like Bedford which is probably too far out for your needs.
There are a number of letting agencies that do not necessarily post on the internet, so it might be worth while doing a bit of foot-slogging.