Unfortunately our templates don't yet support customizing the IP address range. However it seems like an interesting feature that would be great to support in the future.
I have created an internal task for adding this, but unfortunately I cannot give an ETA for when we would start working on this. I will add a note to mention in this topic once started. However, keep in mind this may take some time.
In the meantime, keep in mind you can modify the template manually on your side. In order to do this, launch a template for your favorite stack, go to its Template and click on Add to Library to add it to your Template library.
Then go to Home > Templates, select your created template and edit the ARM Template, change any occurrence of 10.0.0.0/24 by something like 10.1.0.0/24, and do the same process for the other applications (but changing the network prefix to a different value for each one) and save.
Once done, you can Deploy that template with the new network changes. Hope it helps!