For me a DVD is 4,7 GB... but might be different along some countries.
That depends on what you want to do. If you just want to get the file on it and the file is smaller than the DVD can store, than sure, why not? But if you want to play it on a DVD player, you have to convert it to 720 ×576 or 720 × 480 (PAL/NTSC). This will reduce filesize drastically and maybe you can save Bitrate through it, but I'm not an expert at this, there the other people might chime in and tell you the best ways to encode/author a video to DVD.
Also you might be able to use a double layer DVD, wich can hold up do 8,5 GB.
If you want to keep the 1080p or 720p (D+) resolution, then you have to use Blue Ray. These can hold up do 25, 50 or 100GB, so you can store multiple movies on it.
Edit: But for BD you will need both a new player and a new burner, because pure DVD drives cannot play BD. But they are not very expensive. If you are going to purchase a new drive, you might thing about a UHD friendly drive, but of course only if you want to use AnyDVD or even want to buy UHD discs.