Neil,
Keep your eyes open for the 20 and 25 litre translucent HDPE chemical drums at the restaurants, hotels, caravan parks, etc. (anywhere they use cleaning chemicals, disinfectants, detergents, etc)
They are ideal for storing veggie in a dark corner of your garage, easy to handle and can pour into a funnel to refuel your car easily. I use them for my fuel storage.

When filtering, use the top 3/4 of the oil from each drum and consolidate the remainder, which has a high concentration of high melting pooint oils, into other drums. If you have plenty of oil, you can return this oil to the commercial collection container, so that they still get some oil.

Your filter bags will accumulate a layer of high melting point oils (this actually improves the filtration) and flow will reduce. Before the flow reduced too much, you can remove the high melting point oils and return these to the high melting point oil drums going back for the collector.
Using a filter liner, inside the bag filters allows ne to rapidly remove the high melting point oils by removing the liner, scraping it into the solid oil drum and returning it to the filter bag. Most of the solid contaminants will be trapped in the solid oils , allowing the filter bag to remain in use for much longer.

I hope these ideas are of use to you,
Tony
you have email.