A scenario where Gorbachev somehow survives, along with the USSR, carries the problem in that the USSR won't be a superpower any more if he remains. He had alread presided over the collapse of the Warsaw Pact states and was in the process of negotiating a new Union treaty which would have reduced Soviet power in favour of a confederated model. It's also quite likely he would have pulled the plug on the military-industrial complex and any other prestige projects to divert the money to the rest of the economy.