Mind boggling at first eh? I'm still a moron too compared to others here but I have understood some good rules of thumb to go by.
Basicly I'm trying to say, push the battery harder and it is likely to wear out faster. You now have the minimum amp hour size battery to power the motor. If you take it and reconfigure the battery to a higher voltage, you will cut the amp hour size in by one third. The strain on each cell will be one third more. This could be disasterous to the life cycle of the pack. A bigger amp hour size will make the pack last longer, since the strain on each cell is less.
You have 3 , 4 amp hour sub cells in each 3.4v cell in the battery. You could take one sub cell off each cell, and make more two pouch cells and have more volts, but you need a bms, and 16 cell is the biggest one that is not expensive. Surely this will change soon, but not yet that I know about. But anyway, you would still be risking a short lifespan if you make the battery any smaller in amp hours that it is now, even if it is the same number of cells.
As for your length of ride, and recharging. You will be riding farther than you do now, trust me on that. Your routine ride will stay the same, but you will find excuses to take the long way home when the weather gets real nice. Recharging after using just a portion of the capacity is a real good thing. You may double the number of cycles if you use less than 50% each ride. If you use only 33% each cycle, you may very well see 3000 cycles, IF, the discharge rate doesn't go too high. Since you are already using the minimum amp hour size, you may only see 2000-2500 cycles. Its gonna take you years.
Your battery is already optimum for your bike, and in my opinion, a bit small, I'd consider a 16 ah one the optimum, and 20 ah the gold standard. The bigger ah packs will simply last longer, and in the end be cheaper. I thought I had just the right size for my ride, but in colder weather, I found myself pedaling home the last mile with the battery dead a lot. I hadn't given any thought to two things, cold weather cutting my range, and seasonal wind direction. So I harp a lot about no such thing as too big a battery. To go higher voltage you need to go higher voltage and higher amp hour size because the wind drag is going to make the motor pull more amps. A good rule of thumb is one ah ping battery to each amp the controller pulls on average. That keeps you at 1 c. The way to find out the c rate without a meter is to time a ride and ride till the pack is used up. If it takes one hour, you are riding at 1c. If it takes longer, you are under 1c, yay, your battery will last longer. If it takes less than an hour, you are riding at greater than one 1c.
Do you need a battery for your wifes bike? Could it use the 48v ping? If so, maybe you would enjoy nicad batteries or nimh. No need for bms with those so get two 36v packs from ebikes-ca and go for 72v. Those batteries can tolerate the discharge rate better than duct tape lifepo4, so you can get away with a pretty small pack, like 10 ah or so. By the time they wear out, the choices in lifepo4 or lipoly may improve a lot! Maybe even supercaps by then?