You have to request it.
By the way, if three posts is going to consume 80MB, I'd take a good, hard look at your image file sizes - there's a 512MB cap on media. If your site is a travel blog (as opposed to a cleverly-disguised image gallery), then not all of your images need to be features (the equivalent of gatefolds and/or double-trucks in a magazine). Taking some of the image sizes down will allow you to get a lot more content images and "flavour" into your articles without blowing your media cap, and will still let you feature your best and most interesting images. You may want to look at a file optimizer like JPEGmini (or one of the online minimizers) as well; unlike most image editors, they take advantage of the fact that different parts of a JPEG image can have different compression levels, so you keep detail where you need it (without any visible artifacts), but things like wide-open skies can be compressed down to almost nothing when there's no detail there. That can save a ton of room.
If you do need a lot of large images, you're going to have to host them separately at an image hosting site and link to them in your blog (they can still appear on your pages, of course, they just won't be hosted on your website account).
