Just to throw another option into the works, I do a 225 or 250g bag of coffee in a 4 pint milk bottle which is around 1:8. Works great just be aware that it can be seriously strong without you realising because it's not bitter. Have caught myself out a couple of times on an empty stomach.
Can definitely attest to your last point. Drank a litre over the course of a few hours then jumped on the bike, thought I was going to pass out after about 5 minutes.
Just to throw another option into the works, I do a 225 or 250g bag of coffee in a 4 pint milk bottle which is around 1:8. Works great just be aware that it can be seriously strong without you realising because it's not bitter. Have caught myself out a couple of times on an empty stomach.