RAW, you are dead
Xanathar's Guide to Everything states you move 500 feet in the first round* of falling. If you fall anything between 200 and 499 feet, you take 20d6 damage, and don't have time for Wild Shape.
Your DM can save you
Based on your question, your DM is willing to let you use Wild Shape while falling.
Dire Wolf is not enough, you will need a form with 110 - 2 x 34 = 42 HP. There are 2 of these in the official sources:
- Giant Hyena
- Giant Octopus
If your DM lets you take any of these, you not only survive, but you can walk away thanks to Relentless Endurance.
*) This is pretty good physics for the first round. Unfortunately for subsequent rounds it still sets your speed to 500 feet per round, while it should be closer to 1100.
Bonus Action Limitations of Two Weapon Fighting
Raging is a bonus action. If you want to rage, you'll be unable use two weapon fighting that turn. This can put you at a disadvantage right from the start of combat.
Great Weapon Master Bonus Actions
It's not just a critical attack that allows a great weapon master to attack with their bonus action.
On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.
This is still conditional, and will depend on the kind of opponents the DM throws at the party, but mobs of foes and minion types often make appearances in many campaigns and will greatly boost the damage of a great weapon master.
Growth from Extra Attack is in favor of great weapons
With a great weapon, the Extra Attack feature makes you go from 1 attack per turn to 2 (barring great weapon master conditional bonus action attacks). With a two weapon fighter, you go from 2 attacks to 3. So while the damage of the great weapon increases by 100%, the two weapon fighter only gets a bit more then a 50% damage boost (unless you have the two weapon fighting style, in which case, it is a 50% increase).
This same issue also means a great weapon barbarian benefits more from the single extra attack granted by the spell Haste. It also pops up if you decide to multiclass into fighter, because action surge doesn't grant you another bonus action.
Problems created from using more than one weapon
There are many spells you could potentially have applied to your weapon by a party member, such as Magic Weapon
2nd Level Transmutation Spell
You touch a nonmagical weapon. Until the spell ends, that weapon becomes a magic weapon with a +1 bonus to attack rolls and damage rolls.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the bonus increases to +2. When you use a spell slot of 6th level or higher, the bonus increases to +3.
However, this spell and many others only work on a single weapon at a time. So while a great weapon user has all their damage become magical (allowing it to bypass resistance to non-magical damage, which is critical against many foes), a two weapon fighter is left with only part of their attacks improved.
Consider your role in the party
Reckless attack isn't just a risky move, but a way to control opponents. Granting your opponents advantage encourages them to attack you, rather than your squishy wizard friend. With rage, and especially bear totem rage, you can take the damage. If your build is too defensive and never uses reckless attack, opponents may ignore you and go after bigger threats rather then one they can barely hit and can't deal full damage to.
Advantage has a huge effect
This is kind of obvious, but maybe it'll help illustrate just how useful reckless attack is for someone with great weapon master.
Source
If you look at this chart, you can see you have an 75.1% chance of rolling a 11 or higher on your roll if you have advantage. With 18 strength and a +2 proficiency (what you'd probably have at level 4), that's enough to hit 12 AC target, which is the AC of plenty of big beasts and smaller enemies. You'll still hit 15 AC targets 57.8% of the time (without advantage and without the -5 to hit, you'd normally hit 60% of the time with the same stats).
And against very high AC targets, you can choose to not use the power attack and still be relatively effective.
Best Answer
Yes, your Half-Orc Barbarian is nigh-invulnerable to death by falling, as a consumable resource.
Remember that your relentless endurance and your rages both recharge on a long rest. So four times per long day you can take a header off a skyscraper and be pretty sure of living.* (At least for the moment.)
Also, your Bard and Wizard friends can do this, too. Along with five of their friends.
It's called feather fall.
Point being: you can spend your consumables on base jumping without a parachute, and they can spend theirs on doing it with a parachute. You just get a bigger adrenaline rush out of it. (And the accompanying exhaustion.)
*- How sure? Assuming you start at 6HP or more it's impossible to instantly die from rage-jumping massive damage: the fall would need to do 61 damage after reduction, which is impossible for the mere 20d6 you're looking at. You may be at 0HP and looking at some death saves, the odds on which are not nearly as good**.
Relentless-jumping is a little riskier on the front-end, but you do walk away. At full HP you're looking at ~0.0000003% chance of instantly dying of massive damage, at 1HP you're looking at ~13.4%, if I'm reading my first anydice program correctly. It's non-linear between those two endpoints, and in your favor. Check out the graph if you want to see.
**- The probability of surviving death saves unassisted is ~60%.