Science has advanced alot and now bilateral knee replacement are done on regular basis. Also every surgical procedure has its own risk factors, which are quite minimal and must have been explained by your surgeon. If patient is surgically fit, they can go for bilateral knee replacement. Regarding corona time, if you pain is unbearable then you have to get it done, else you can choose time of your liking.
Next Steps
make up your mind, when you want to get it done