If you put in less honey it may not have the quality of a mead. It may be more like an apple wine. Your call, of course.
How to backsweeten? After the active fermentation has ended (so the gravity is about 1.000 or less and you have racked the wine or mead or cider off the yeast, you add K-meta and K-sorbate. The K-meta can kill a small colony of yeast and the sorbate prevents those that survive from reproducing, so you can add any sugar you wish and the yeast will be unable to ferment it - more apple juice concentrate, honey, table sugar, corn sugar, etc. Best to bench test to determine how sweet you want it. Easy to add more sugar , not so easy to remove it once added. Per gallon, you might want to add about 4 oz of sugar (to bring the final gravity up to about 1.010 -1.015 but you may like it more sweet or more dry (less sweet).