hm. Surely SARS-CoV-2 RNA sequence for one virus itself isn't 300gb? does it contain multiple variants or unprocessed and unjoined fragments?
But to answer your question about "one virus", the initial isolate of SARS-CoV-2 from Wuhan, China has a genome containing 29,903 nucleotides. You can see the full raw sequence by clicking on "FASTA" on this page: https://www.ncbi.nlm.nih.gov/nuccore/1798174254
That seems clear enough.