linux kernel driver, how to resize allocated character device region

Question

I'm learning about linux kernel drivers and I am confused about device major/minor allocation. Especially the case in which I am not aware ahead of time of the number of devices I would like to manage.

Indeed, I know that we may allocate multiple devices at once dynamically with

alloc_chrdev_region (
   &dev,
   ALLOC_FIRST_MINOR,
   ALLOC_COUNT,
   DEV_NAME )

But I wonder about situations in which ALLOC_COUNT might not be obvious ahead of time.

Question

How do I re-size an allocated character device region ? Is it common practice to do so ?

Concerns

Large allocation drawbacks

Is there any drawback with taking a large/safe amount of minors and call cdev_init on a few of them only ?

Small allocation instead ?

If so, should I allocate small number of device first and then later allocate more if necessary later ? Is it something seen in the wild ? the last argument makes me think that I would be doing something wrong doing that.

What I Have Tried

Mutliple call to alloc_chred_region

I quickly run out of MAJOR numbers and I conclude this is not a very good solution

Multiple call to register_chred_region

I thought to make an initial call to alloc_chred_region which would give me a sentinel with a major dynamically allocated and then call at need register_chrdev_region to allocate more device number some time later. While much better that its counterpart, it doesn't fix any of the concerns.