Im in this area as well with a 1 mb modem. Usually I play with around 80ms - 100ms with no issues. However in the past 2 weeks iBurst has deteriorated and Dota 2 has become unplayable. Now my ping is almost always above 200ms. Tell your friend to wait it out until iBurst fix their sh*t and to also get an antenna because that should help stablise the connection.