Empower Familiar

You can empower a familiar in your service, provided they were acquired by the Find Familiar spell and in range during the casting.  Your familiar gains a bonus, to equal to your proficiency bonus, to their Dexterity, Constitution, and Wisdom ability scores. 

If your familiar drops to 0 hit points, you can preform a ritual as part of a short or long rest to recall them.  It reappears within 10 feet of you after your rest is complete. 

The distance at which you can telepathically communicate with your familiar, or see and hear through its senses,  increases to 1 mile. 

As a bonus action, you can temporarily dismiss your familiar.  It disappears into a pocket dimension where it awaits your summons.  As a bonus action while it is temporarily dismissed, you can cause it to reappear in any unoccupied space within 30 feet of you.  You can still dismiss your familiar forever, and if a new familiar is summoned you would need to cast this spell again to empower it. 

You still can't have more than one familiar at a time.  If you cast Find Familiar while you have an empowered familiar, you instead cause it to adopt a new form.  Choose one of the forms listed in the Find Familiar spell and it transforms into the chosen creature.