Have Mule, Will Travel

A mule is a crossbreed of between a horse and a donkey. Mules are stubborn, and if bothered or excited they may either bite or kick... Mules cannot be trained to attack, but will fight in their own defense.
-The Red Book of Moldvay

When your adventure takes you out to the middle of the wilderness, you don't want to be caught short of food, torches, oil, or any other supplies. Every journey back to town is time wasted - and that means chance encounters rolled, and opportunities for death and mayhem without the payoff of treasure. The best way to maximize your carrying capacity without slowing the expedition to a crawl is to load up the extra gear on a mule.

Here's my super-clever Mule Record Sheet:

Obviously I have played Diablo II a few times

If a PC's backpack was laid out the same way, it would only have three or four rows. So, like, a mule can carry a whole lot. If the party is traveling on foot, their usual movement rate is the 60'/20' speed of a fully laden mule, so that's handy. However, if the party is riding horses, their movement could be significantly faster, and they might be wise to ensure their mule never slows them down below 120'/40' speed.

By my encumbrance rules, every item takes up a whole slot - every torch, every day's worth of rations (for each person!), to say nothing of bringing feed for the horses. As great as the mule's carrying capacity may be, sometimes you need an expert to do the packing for you. For a proper adventure, you'll want to hire a teamster or a carter. A carter can pack bundles of objects (such as a week's rations or a six-pack of torches) to take up only two spaces on the Mule Sheet. The carter will also tend to the party's mule and horses during travel and while camping, but will need an assistant if tending more than six animals.

The best carter in Sham is Randol, and he normally charges ten silver pennies a day, twenty if his assistant Maya is required. However, he has been known to offer discounts in the past provided that his employers cover all necessary expenses (food, camping gear, etc). The negotiation will depend on a Reaction roll - a good result will get the discount, a neutral result will require further negotiation, and a poor result will see him stand firm - or possibly insist on some additional 'hazard pay' for traveling into the heart of Kruthar territory!