I always take a horse water trough to elk camp if I am not right on a river or creek.
A good trick for elk is to field butcher into the upper lags and saddle portions, and set them in salted water to leach out the blood. it keeps the meat from souring and cools it fast. After 1-2 days (depending on weather) in the water, you can then dry off the pieces and hang them in trees to case and you'll have good meat
I have handled a LOT of elk in the last 35 years or so.
I can give you a few tips on ground dressing skinning and field butchering. I have done so many that i am fast at it.
last year my friend Steve times my processing of a big cow buffalo he shot. From the time he fired to the time it was skinned and field butchered was 25 minutes.
If you know a few tricks, it's not hard to do, the skin is whole and the meat is perfect.
E-mail me if you'd like to talk