Can you just do half of this recipe to make a smaller loaf, or will that affect the procedure?

Short answers - yes you can do half recipe, no it won't (much) affect procedure. Some rising times might be slightly shorter.
But why are you making only half?
If you have enough flour and expect to need the bread within the next three months, you could make the whole dough, divide and freeze half for future baking.
If not, not.