First off, yes there is battery technology to bridge the gap. Solar+battery storage is an increasingly common purchase for utilities today, there are home-batteries for purchase for consumers from multiple companies. To say battery storage doesn't exist and isn't cheaper than oil/coal grid power is simply false.
Second, renewables can have higher capacity factors than many fossil-fuel plants, so saying they're intermittent and fossil-fuel is not is false. Surely, solar is weaker in winter, but wind is stronger at night, and seasonal storage is the main issue here. Yes, we will be using natural gas for winter and certain Northerly regions for decades to come, but it will become increasingly niche/reserve as batteries, solar, and wind get even cheaper.
Renewables absolutely do not need to be paired with natural gas to make it "remotely viable". There are numerous markets with very high % of renewables already, and it turns out utility operators are very smart and know how to plan very well. Renewables can reach very high market penetration, given solar is a day resource and wind is a night resource, in general. The main issue is bringing demand response online to tailor your loads to fit your renewables: charge EVs, batteries, use AC/heating, industrial processes, all can be tailored to the price of electricity, given a smart utility.