The speed limit is c. It's the law.
Absolutely. I too feel this is a pretty well-established fixed upper limit on a body's physical speed through spacetime.
Of course, I live in hope that Humanity will eventually develop methods to 'skip around' the pesky limitations of physics in the universe as we currently know it. That said, no evidence is available to assist me. Even if such a thing is possible we might be talking about a technology tens of thousands of years ahead of our current tech level.
Perhaps in time we'll learn to employ gravity with similar ease to our methods for utilising the electromagnetic force. Likely, this will be only one of many, many prerequisite technologies needed to achieve interstellar travel.
Without the tech itself we can only speculate. However limited we are, the beautifully elegant Alcubierre drive concept (which we're all no doubt familiar with) was still the product of an imagination of our time, even as desperately limited as it is. Some Humans are really very clever. We may well yet crack this nut, only time will tell.