It is not certain whether Venus even had water or not. The planet has always been volcanically active, and as far as we know, has never had life on it. We know (or at least are pretty sure) that liquid water can't exist on Venus because of its proximity to the sun. No liquid water likely means no life. No life means no conversion of all that CO2 into Oxygen. CO2 is a greenhouse gas and a significant contributor to rising temperatures. If the CO2 has always been there, then so has the planet's greenhouse effect.
Given external temperature from your planet's star, I might give it anywhere from 100-200 years or so. Water will not help much here because if your planet had life then it will also be cold enough to have liquid water. In this case water would act more like a moderator of temperature than a contributor to a runaway greenhouse effect. You will still have a greenhouse effect, but at the very most, it will just mean your people will need to adapt to the surface conditions rather than hide from them.
Changing the planet's environment in other ways might make a difference, though. Earth has been through several greenhouse effects in the past and its surface wasn't destroyed then, making me think that you may need something extra that wasn't there before to create the kinds of conditions you are looking for.