Have you considered OoID instead of Winter Flurry? Should be like a ~3.5 tier damage loss without any other changes , but with OoID + Karini you’d be able to tank anything!
I suppose the damage loss might be too much for low paragon 150 though.
I’ve got the cache start pretty reliably down to 30-35 minutes (necro to 18, farm diamonds, then swap to wizard). I was the third person on NA to level 70. After that I did top 10 for all 5 conquests, that was pretty nice!
Going necro to 18 speeds things up quite a bit (I just delete the necro after), necro is SO much faster than wizard for that 1-18 stretch. Corpse Explosion unlocks at level 4 and is just stupidly strong for levelling. You can basically just make a level 1 necro on Master or T1, steal the templar’s weapon (and leave the enchantress untouched so you can steal her weapon later at level 11+) , salvage the templar’s shield and the scoundrel’s bow to get your parts for the first step of the altar, and run to the cube. By the time you get the cube, you’ll be 18 (or close to) and you can farm the diamonds and swap to wizard. At that point with some higher level gear on your wizard (whatever your necro was wearing, plus the highest level weapon you can craft from the blacksmith) you’ll be back to 18 on the wizard in no time. It ends up just being straight up faster than going wizard from the start. If you’re a lifelong wizard, it can feel a bit dirty, but it works. Magic Missile and Ray of Frost are just so slow to start compared to Bone Spear/Corpse Explosion.
Wizard doesn’t get decent for levelling until Disintegrate + Teleport in the 20s. Jump starting with the necro ends up working really well.
If you’re willing to be flexible with LoD start, you should be able to gear pretty quickly. Any 2 items for meteor/orbs/hydras/twisters/EB should get you going. Do a vision or two to get a few GR keys, run GRs to get LoD gem (it will usually, but not always, be the second gem that drops), and off to the races. Biggest thing is not to get too hung up on targetting one particular build, just roll with what you find. I usually just dump all my shards into sources and all my DBs into wands. That’ll pretty efficiently cover items for all the main builds except meteor. If I get a lucky Nilfur’s or Mempo drop early, then I’ll usually switch gears and start upgrading staffs to go for meteor instead.
A level 15-25 LoD and any two multipliers for the main builds should get you pretty easily to T10/GR40. A 25+ LoD and a third multiplier for one of those main builds should get you to T13/GR60, at which point you may be more limited by survability unless you get an early Karini, but then you can hang there for a bit and farm set pieces and/or a RoRG.
I ended up doing LoD EB this season because that’s what I got. Definitely my least favourite of the big skill multiplier options, but I just worked with it because I got a Wand of Woh on my first wand upgrade and gambled an OoID.
I was at GR45 on SSF wizard before any other SSF wizards registered a GR clear: https://i.imgur.com/abDIATP.jpeg