<font face="Verdana, Arial, Helvetica, sans-serif" size="2">In the former west, Germans mostly speak some English, but that's not so in the east where you'll be travelling</font>
It is certainly true that English is not as widely spoken in the East as it is in the West, but younger East Germans will have the same command of English as their contemporaries in the West.
Under the old system Russian was the compulsory first foreign language, taught from about age 10, and only those with top marks in Russian were allowed to learn English as their second foreign language. Nowadays English is generally taught first, so all East Germans under 25 will have learnt English at school.