T-Mobile Network 4G LTE Reduced Slow Speed Demo (Throttled Data Plan to 128kbps)
128 kbps is not fast, but over good carrier technology, it’s serviceable for very light use. You wouldn’t stream video over it, but web browsing, maps, and so forth would remain usable, if slow. You certainly don’t want anything happening in the background, so disable automatic updates on all your devices first.