Does the temp HP you receive from Bear Spirit last until the totem vanishes, or until a long rest? Thanks!

Oh wow, that seems very useful! Could you have the whole party do a long rest, set the totem down, do a short rest, then just do another spirit totem that isn't bear cause everybody has temp hp?

That will work, but you miss out on a great benefit: Pumping your conjurations!

Combat begins: Summon 8 wolves (Action) then call forth your spirit totem (Bonus Action) and everyone in your party, and your 8 wolves, now have the Temp HP, then the wolves attack! Plus at 6th level your conjures gain an extra 2 HP / Hit Dice. 

When my 6th level Shepard does this each wolf she conjures has: 11 HP (Wolf) + 4 HP (Mighty Summoner) + 11 THP (Totem). That's 8 wolves with 26 HP each and pack tactics. 

It's generally better to summon giant poisonous snakes for the combat, as they have greater damage and more hp

https://www.dndbeyond.com/monsters/giant-poisonous-snake

They've the same HP, do 1 point less of average damage, but holy carp that poison damage (even on a save) is pretty sweet. Thanks for the tip!