It's a non-issue with a big enough pot. Besides, the wort is sugar based--washes right off. The burner is high enough that it doesn't "bake" or "carbonize" the spills like a stove-top unit does.
I set my burner and 20 gallon kettle on my patio table (of course, it is sturdy--it's made of steel and tile, not vinyl or plastic)--it makes transfers into the fermenter a breeze after IC/whirlpooling.
If you're still worried, just put aluminum foil around a section of cardboard and set it underneath your burner and kettle. Your drip pan would be better used as a large sanitized area to put spoons and thermometers down on during a brew day or bottling day.