It is never a good idea to exhaust a battery completely, over compensate considerably as you never know about weather conditions that would require ventilation to prevent misting,repeat cycle charged to dead can damage the battery, be wise not stranded.
Depleting your HV battery isn't possible!!
Mr MG along with his mates at Mr Tesla, Nissan, Renault and all EV manufacturers have made sure that 0% isn't 0% or a flat battery!
At 0% there is about 4% of capacity left, some allow for more some have less, in the battery.
It is the same a 100%, that is NOT 100% but about 95%.
LG and the other battery manufacturers are constantly making amendments to the 'seen' capacity to prolong battery life.
At the outset caution was the byword and 10% was left in a battery that showed 0%.
There are plenty of 300,000 mile Tesla Model S's around that have done this mileage, usually 2013 - 4 models, and their batteries have 85% capacity or more left in them.
You can be sure that some will have been driven to the 'no more miles' point on the battery!
So DON'T worry about knackering your battery if you constantly deplete it to 1 - 2 % if your nerves can take it! The battery certainly can!