Have temporary outdoor Yurts built in parking lots allowing the accommodation of diners. Hot bags could be used to move food.
The idea involves building temporary heated yurts in the parking lots of restaurants that allow for small numbers of diners. We can use resources from festival tents Yurts could be build with separate areas separating diners or as individual units. Food could be moved in and out through hot bags and diners can place orders via mobile. A simulated restaurant environment can be created with speakers emoting dining sounds, ambient dining noise and even internet connected cameras into the restaurant kitchen. Yurts can be hooked up to a central heating element or have individual heaters.
The solution allows diners to be kept separated but comfortable. The city can have dining through the coldest times. Yurts can be construed and deconstructed in a day. All other distancing and sanitising guidelines kept as well.
The greatest challenge is the cost for the tents. Perhaps recycled building materials and resources from festivals that are no longer being held. Many companies have tents that are not being used all the would be needed to to enclose and heat them.
Prototype a simple to set up guide for building a yurt and a quick assembly kit .