One of the things I learned from the new Gershwin bio by Howard Pollack and also from my conversation with Ernie Harburg, was that the Gerswhwin's were fairly well off compared to other immigrants. Block makes reference to the family living in St. Petersburg, Russia rather than in the shtetls of the Pale of Settlement. In St. Petersburg, Morris, George's father may have been exposed to more modern business thinking. Like other immigrant families they may have moved a lot, not because of financial hardships, but rather so Morris could be closer to his many businesses. In 1910 they lived in this fairly new and spacious apartment house that still stands on Chrystie and Grand.
Here's a portion of the census where the family was listed as the Gershvens