How soon do I need to replace battery once "Service Battery" notice appears?

This is regarding a 2015 MacBookPro

Battery Information:

Battery Health Information: Cycle Count: 723

Condition: Service Battery

I use MBP plugged in most of the time, but maybe an hour per day unplugged.

How long can I go before replacing battery. I want to get the most out of the current battery.

Dread having to have MBP in the shop.

Thanks in advanced for your help,

ikwin