It depends on the computer doing the work. Basically, you want to transcode the video file. This is extremely CPU intensive computational work and the resulting high definition video file will be anywhere between 4x and 8x larger than the original file - depending on the codec used for the transcoding work.
Quick math: Uncompressed standard definition video consumes about 14 gig of computer hard drive space for every 60 minutes of video. In round numbers your file, if uncompressed, would be about 21 gig. Transcoding to high definition video (again, uncompressed - we don't know which codec you want to use) can range from about 80 gig to 160 gig or computer hard drive space. I suggest you use h.264 codec when doing the transcoding... BUT, here's the rub:
After the hours and hours of transcoding, the video quality will not appear to be any better that the original standard definition file, so there isn't really any point to wasting the time, electricity or hard drive space for the much larger high definition video file... Just because the file is 1080 horizontal lines of video resolution does not make it any better than when it was the 480p source file. The subsequent generations can only be as good, visually, as the original file... in this case, standard definition 480p video.
To have video quality that is 1080 horizontal lines of resolution, you need to start with 1080... or higher (i.e., 4k) and downsample. Upsampling (what you propose) will not provide you with the results you want.