Josh, I am not too sure which snow shoes you are using, but I know that I could attach both of my MSR EVO Ascents to the same side of my Pinnacle? I can also do this is on my CCW Valdez & Chernobyl, as well as my BD Speed 30 and my friend's Variant 37.
This leaves one free side to attach anything else that you need (probe, crampons, microspikes, pickets, tent etc)-- in your case this would free up the side pocket for your water.
If you are unable to do this, then look at:
1) Using a 'biner to affix the nalgene to somewhere else on the pack in a nalegene cozy.
2) Putting the nalgene inside the pack, wrapped in your down jacket.
Most people that I know do not use the hose on their bladder due to freezing-- but packing the actual bladder is just fine, just discard the hose and put a lid on the bladder.