You can probably find some tests online for the high current performance of AA cells. It depends a lot on the design and quality of the cell, but most good quality AA cells should manage 5 A comfortably, and some can get up to 10 A. But at that discharge rate the cells are quite stressed and will also get warm. Consumer products are unlikely to run to such high discharge rates, since if you did run a 2000 mAh cell at 5 A discharge it would barely last for 20 minutes. Not very useful if you want to wear the ski boots for a few hours.
Your best estimate would be to divide the battery capacity by the run time and use that to estimate the current draw. And I imagine the thinner nickel strips would be fine.