The 'internal resistance' of the battery - often assumed to be measured by the Hx reading in LeafSpy - makes a big difference in how much the battery heats up when charged or discharged. The 40kWh packs do seem to have much more stable Hx readings than the 30kWh packs. So if that is truly a measurem...
3/16 ID x 5/16 OD vinyl tubing works well. Clear tubing is nice so you can see the fluid inside. As for the jar, any old bottle works. Plastic is nice so it won't fall and break. Many auto parts stores will recycle the old brake fluid or if you have a household hazardous waste place handy they will ...
You can probably find a wiring diagram for your Leaf at nicoclub.com. I'd look through that and see what circuits are powered by the fuses and/or warm relay you mentioned in the OP and try to determine if they are malfunctioning somehow.
It will certainly make it one way but if the charging stations are down or unavailable for some reason, doing a round trip would be nerve racking, IMO.
The 120V EVSE that came with the Leaf puts roughly 1.2kW into the battery. If you only use 2kWh per day and you want to keep the SOC in the mid-range (as usually recommended for battery longevity) you could adjust the start or stop time as GerryAZ mentioned so it only replaces as much energy as you ...