Yukon HL, 1 watt mod to 3?

Please excuse me if this question is ignorant. I just used my Yukon HL for it's intended use, and although I like the light, there just isn't enough. What concerns/considerations need to be addressed if one wanted to replace the 1 watt Luxeon with a 3 watt one? The only issues that occur to me are battery life and heatsinking. Can anyone in the know address these two issues and any others I may not have considered? Just looked at the Luxeon catalog before posting and can't find a 3 watt side emitter, only 5 watters. Thoughts?