UPDATE: With my typical settings on a brand new map I just made, I solo spawned next to a POI that had 2 water bottle loots, but also a ditch filled with it. It's not even 1pm yet in this playthrough, and im sitting on 4 murky waters, 2 clean ones, 5 canned foods and 1 cooking pot.
I only looted the Trader Rekt that was in my opening quest line, and a moes grocery store. I'm swimming in arrows and was lucky enough to loot t4 leather punch gloves. I'm 2% into an infection, but there are stumps all over. I'm in a massive city complex with farms on the outskirts in the forest biome, and I've already set up my cozy little backyard base until I can move into something that isn't made entirely of wood and good intentions.
So not only is it possible to survive, but I consider this a better than average start. Maybe RNG was on my side, or maybe its the fact that I know what POI's to look out for an loot before I go all cowboy and get myself into a bad situation.
SECOND UPDATE: After looting a t1 Pass N Gas, I'm now up to 7 murky waters, and I've drank 3 so far. I was lucky enough to loot one yucca juice which went down right away. I've hunted about 5-6 chickens and rabbits so meat isn't an issue. I've started to cannibalize Moe's Grocery for usable materials because its hour 2100, and soon the sun is gunna go down. Might as well have a few walls between me and the first night ferals (I actually turned on feral sense at night as well).
So again, literally.. warrior difficulty and vanilla loot settings im having no issues other than concussion debuff, which.. if that's the worst thing to come out of my first whole day then I'll take it. This is all without taking any Trader Quests so far. The next day I might do one or two buried supplies, but I already started working on farming and then food could become a non-issue within 3 days.