Is it possible to play on Legendary straight off the bat or is it virtually impossible?

Any strategy/tactic you recommend to survive legendary? Xbox player. no mods or cheats please

It seems that most would recommend that you wait till lvl 20+ before switching to Legendary mode.

Wud that mean that it is viably impossible to start on legendary?

Well... yeah maybe... no.

You can start Legendary from lvl 1 sure, BUT you are likely to get your ass handed to you by simple starter bandits.

It's possible but very difficult. I started a new game and didn't notice I was at legendary until level 16 or so doing one of the quest lines and wondering why it was so difficult. I kept on having to swallow potions and was running out, then I checked the difficulty and had to drop down to master. To survive at legendary you'll need a companion and have them tank for you. Then summon a fire elemental or frost, I like fire because of their ranged attack. Don't engage enemies unless they are already fighting one of your allies. That way you don't get hit. If you do have to fight, you'll need plenty of potions. You'll have to stock up on a lot of health potions. Besides the health potions, paralyze is a great poison--only it doesn't work against undead. Slow is another good poison to use.

You'll have to avoid some of the quests that make you go into long dungeons with tough enemies until much later when you're in the 30's or 40's. Otherwise you can just go off and kill dragons, fortunately they are easy at any difficulty as long as you have fire/frost resist potions. Legendary becomes routine when you can craft Glass armor. I never use heavy armor so I don't know the equivalent spot. You don't need to use exploits either in crafting, just simple glass. Legendary becomes easy when you can double enchant so you can stack magic resist with other buffs and have absorb health plus shock or whatever else on your weapons.

I've just switched to legendary again after reaching level 40. It seemed harder this time, maybe because I'm using mods that increase the difficulty of enemies. I have not bothered to fully enchant smithing gear, I have gear that I enchanted with common gems as throwaway practice enchantments. I haven't deliberately grinded any skill so I can't double enchant yet and just got to glass on smithing. I don't use potions that boost smithing either or enchanting.

In short, it's possible, but very hard at the beginning, you'll have to pick and choose the places you want to go and save some quests until later.

It's doable. I was just playing my orc warrior who has played legendary since level 1(level 46 now with no more level ups to be used) and hasn't died or used a single potion. I've only used melee as well, no archery or sneak employed. It's really all about knowing your limits at lower levels and recognizing when the NPCs have "leveled up" to the point where they outclass you. My best advice would be to stay away from bandit chiefs with 2h weapons at lower levels since they can sometimes trigger a kill cam on you without even hitting you first(stupid mechanic.....), and try to get some magic resist ASAP(lord stone, agent of mara, etc)for dragons and enemy mages. Things like dwemer ruins and crypts are "safer" at lower levels because of the fact that the enemies can't kill cam you like described above...use this to your advantage

You don't necessarily need a companion(I actually despise them due to their bad AI and never use them) either as long as your tactics are sound