You can have it on multiple devices at the same time (computers, phones,...), there is a special "saved messages" channel for files, it can easily accommodate small to reasonably big files (like GB files), and there is also a webclient that you can use in a few seconds if you are not on your trusted computer.
You can also delete the file once you are done. The only problem is that you will have to trust Telegram for having you data. But I guess that if you are ready to trust WeTransfer or Google drive, it is not really different.