I was first aid instructor with St John's ambulance brigade for some 15 years but 20+ years ago when I was in school.
In my NS days I used to kill cobras 20-30 of them. Especially during exercise or night prowler duties. Many black cobras in SGP, Sembawang Camp Changi Camp SAFTI exercise areas. Usually 1 meter size. I chase them up and accurately step on their head to squashed them. Larger size can not do this trick. SAF boots not powerful enough.
In SAFTI live fire hills I saw a huge black cobra, the thickness was like adult upper arm 3+ meters. It crossed our dirt path in front of our landrover, I got off the veh to look for it but not found. There must be a hole it got hidden. Snakes not so risky there as SAF blind bombs, got countless number of mortar shells around.
For 1st Aid when medical help is too far away and patient could died of heart failure before reaching hospital. Can consider to BURNT the WOUND. Open the wound after tied to stop bleeding. And press hot burning metal against the area containing venom. The venom is bio-toxin meaning it is also protein, and it can not withstand heat. You cook it and protein will disintegrate into something else less lethal.
Burn wound is usually not lethal, far less lethal than snake venom. So if hospital is few days away, you rather have a bad 3rd degree burn rather than a corpse of with failed heart, burn the snake bite. The snake bite is already more painful than the burn itself anyway. :p Ouch!