What if during Gorbachev's reign, he instead reformed the USSR to a much more mixed market economy oriented Russia? Similar to Xiaoping, however It's hard for me to decide whether a mixed market USSR would still collapse, after all when the people of the USSR were exposed to the outside world, they led the collapse. With the internet a few years away it's hard for me see the USSR staying together, however, I look at China and I honestly have little to no idea how they managed to prevent any revolts.