With the dual voltage EVSE that Nissan provides, I agree with the OP. It's pretty easy to wall mount the stock EVSE, in which case it can be left plugged into the 14-50R all the time. I wouldn't just dump it on the lawn though...
Because you never know when you might need one, I would be inclined to purchase a cheapo 120V EVSE from Amazon and keep that in the car "just in case"...
An example, not an endorsement:
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV