Our local dobbies (tesco garden centre) sells these little round logs, billed as green and burn hotter, they light relatively easy and are a lot cleaner to carry about than coal. They burn a lot hotter than most logs you get, and wood from different tyoes of tree all burn to varying degrees, I forget which is best Ash as I recall works well as does oak which burns slower and some conifers burn well with a pleasant smell, but if I were travelling which it sounds like you are, I’d take a £4.99 bag of these dobbie wood fuel composite things for wood burring stoves..
Coal does still burn hottest but takes a bit to get going.
Anthracite burns hotter still.