What size kettle is right for my burner?

[Manholebrewhause]

Ok so I am finally moving my brewing outdoors and expanding to AG after 2 years of extract. That being said, I will need to expand beyond my current 6gal kettle. The problem I'm facing is that the propane burner I have is only 14" square. Most of the 12-15 gallon kettles are 18" or larger though. (I'm hoping to eventually do 10gal split batches or multiple kegs one day). Is it possible (or even safe) to use a kettle larger than the burner, or should I just stay small and ditch the 10gal idea?

 

[estricklin]

I'm using a Concord 25 Gallon kettle that's over 20 inches wide, on my turkey fryer burner. I've had 18 gallons in it before, haven't had a problem. The pot being wider actually seems to help with heating if you can believe that.