Cuts like these are all based on experience and technique, so to ask if it is possible.....
If the glass is a buttery smooth, cathedral, handblown or super machined (spectrum) I think it could be done with a glass cutter and a good pair of grozing pliers and confidence.
If you are new to the game, or not as experienced with chewing off the glass with pliers I recommend practicing on clear window glass, cheaper and easy to cut. I have several different sizes of grozing pliers to help with smaller areas that need removed.
Sometimes when I am doing a restoration I come across a piece that is cut at such an angle, or curve, or both, that I am really blown away. 100 years ago the option of taking the glass to a ring saw or grinder was not an option. I like to joke that they used their teeth to get the glass cut sometimes, that is what it looks like when you chew away mass with pliers. Give it a try sometime, if you get the hang of it the grinder becomes a thing of the past. I try to razz my newbies anytime they use the grinder, they learn that the cuts are able to be made with hand tools and it ups their skill immensely!