Most of the greenhouse effect warming takes place in the summer, for the simple reason that's when the most solar radiation is received and trapped. This doesn't eliminate that effect, it offsets the increase in the *average* by adding an unnaturally cold winters -- which by the way would increase fossil fuel use dramatically.
Now this would -- if it is physically and economically feasible -- blunt *some* impacts of global warming, such as glacier retreat and sea level rise. But it would accelerate *other* effects, such as habitat loss and changes in rainfall. Other carbon driven changes like the emergence of carbon-loving weed populations would continue unabated.
Consequently assuming that it's practical, its effects would be at best mixed, and there would be some big-time winners and losers. People with a lot of money in waterfront property would be big winners; interior farmers who rely on historical rainfall and summer temperature patterns would lose. Trout fisherman would lose as warm-water species outcompete salmonid species in their historical range. Etc.
These kind of problems are inherent in any attempt to treat the *symptoms* of rapid, anthropogenic climate change. I you aren't going to use conservation and efficiency to attack the problem, then the most promising geoengineering solution is carbon sequestration -- if it can be achieved on the scale needed. In the ideal case you would set the CO2 levels back, say, to 1960s levels. Not necessarily pre-industrial, because people have already adapted to changes from pre-industrial levels, but low enough that the rate of climate change is closer to natural than what we have today.