If the hardliners had somehow managed to pull off their putsch, they'd be faced with an economy deep, deep in the tank, a society coming apart at its seams, little to no credibility with ordinary Soviets, little to no popularity with foreign governments, and active dissent all over the place, including quite possibly ethnic riots in places like the Baltics and outright violence in, say, Georgia. Not pretty.
They certainly don't have the resources to undertake the conquest of the satellite states. NATO would decisively warn them off if they even raised the possibility (given that one of the states was voluntarily annexed by a NATO member, any reversion to the status-quo implies an attack on Germany, soooo...), to say nothing of those states, many of them euphoric in their newfound independence (the only one where the Soviet-imposed system was anything but politically bankrupt by 1989 was Bulgaria which, to say nothing of how good invasions are for destroying old sentimental ties, is also behind Romania). These countries all had functioning militaries, mind. In Romania, indeed, it was the generals who had overthrown communism.
So while it's pretty obvious that the Soviets would never succeed, why would they even try? Not only are there hands full enough already, but the decision to dismantle communism in Warpac was taken most importantly in Moscow, and the Kremlin had carefully micromanaged the evacuation of its military forces to prevent any potential complications. Obviously Gorby's policies were not terribly popular with the hardliners in the putsch, but when you got down to it, Warpac had been a gaggle of unsound parasite-states that had been kept alive economically by Soviet goodie-bags. In the early 1990s, the USSR was in no position whatever to distribute goodie-bags.
So in short: sorry, no chance. Warpac was gone for good.