My friends in Russia say it's no problem at all. At first they were apparently blocking millions of IP address (mostly Google and Amazon) to try and get Telegram to stop working. It did more damage to other sites than to Telegram. After a while the removed a lot of the bans. I think Telegram is still officially banned, but my friends say it works without even using a proxy. Seems like they're doing a horrible job at blocking it. That and/or Pavel Durov is just doing a very good job at avoiding the block.