unsure if this is viable using IPFS given the file size?

There is no technical reason why this wouldn't be possible. 4K is somewhat of an arbitrary term which essentially means higher bitrate and higher resolution. The file size the more important thing to consider. IPFS can theoretically support practically unlimited file sizes. Now, the more relevant factors to consider are internet speed/how you will be hosting this data as it would determine the quality of playback for the end user.