Update on the question/solution.
Currently, the best setup we have identified and tried so far is Azure virtual machine scale set. We tried the scale set with the load balancer in front of it but the load balancer has a limitation on the number of inbound rules that can be configured. So we are using scale set without the load balancer. For storage, we are using azure storage account v2.
Mediasoup documentation has one section on deploying it on the docker container instance. I am yet to try it out. Once I try that, I will update the answer accordingly.