It is frustrating having to wait for a response from the DVLA when reapplying for a licence but unfortunately this is not an uncommon occurrence. The DVLA do not give a waiting time for licence renewal or reissue on medical grounds as the amount of time taken to process can vary significantly based on the complexity of the case. You could contact your insurer to see if they will pause your cover, but that would mean your vehicle was uninsured against theft or damage while on your driveway.