Will I be able to play my Steam games when I move from Russia to Germany? If not, what can I do?

According to Reddit you can get locked out, but you can contact Steam support to get your games back:

Hello fellow Russian.

I've moved to the EU several years years ago and had some games which were locked-out. Here's what I've done: I wrote to the steam support and asked what can I do about it. I got asked the following scans: ID, Address Card and a paid bill for this address. After this my locked games became available to me.

I've moved from Russia to US and I have no problems playing my games or buying new ones.

Well, I have to accept an answer that "worked for me", so I have to write my own: not a single problem I have seen, even though I had a RU/CIS version of, for example, Bioshock Infinite. I can still install it (the button is active, the download starts) and likely also play it (I don't want to download 40 GB to test it now).

Probably because Steam didn't receive a single German payment from me yet, probably because the game was bought pretty long ago (summer 2016). But I will watch what happens later and check if it still works.

What is also interesting: when I open Steam Store, at first it shows me the price in Euro, but after ~1 second the page refreshes and I start to see it in Russian rouble.