Rooms at the Oberoi Grand are not good, dated and small bathrooms but the service and food makes it probably the best choice in Kolkata.
The drive from Chandigarh to Shimla is not for the faint hearted but Wildflower Hall is wonderful, The Cecil did not look as good but only went in to use the loos! You can take the take the train but make sure you book the first class carriage.
The Taj Nadesar Palace is very good and great to go back to after the chaos.