If you must drainy, drainy (I must) and can't bring yourself to acquire a proper-capacity pan, here is an idea that may help.
Get a strong piece of cardboard about 4-6 feet long, just a couple of feet wide. A piece cut from an old appliance box is ideal. Put your two pans near one end, running lengthwise. Slide it under the car so the front most pan is aligned with the plug and start the flow. (The other end of the cardboard will extend out to the front.)
Keep an eye on it, and at the proper time just pull the cardboard forward, sliding the fresh pan into position to catch the remainder. As an added bonus, if any slops out, the cardboard will absorb it.
I don't do that for oil changes as I have the correct-size container. However, I often slide a piece of cardboard under when I'm working on the car for insulation (cold concrete is no fun) as well as catching drops (fuel filter, trans connector, differential fluid, etc.). Then I just leave the tools laying on it and slide it all out at once.
As has been said before, YMMV; I just toss it out as an idea. Absent rocks in the way that would probably work for Kajtek1 on dirt, too.