There seems to be some confusion regarding this topic. Hopefully this post will clarify some of that.
The first thing to note is that SS utilizes a CDN(content delivery network) namely Cloudflare.
So what does this mean? Well when you try to access SS from your web browser(assuming your DNS settings are "typical") your web browser will perform a DNS request. Only since SS utilizes Cloudflare the DNS server will return the IP address of a Cloudflare server where a version of the SS website is cached. The IP address that the SS DNS request resolves to thus depends on your location furthermore multiple websites will be associated with that particular IP address as Cloudflare hosts more websites than it has IP address. Furthermore it should be noted that the SS host server's IP address is unknown to the public as all DNS requests for SS will be resolved to a Cloudflare server.
Ok, so what? Well if the UK government tries to block the SS IP they will have a very difficult time as they do not know the true IP of SS and even if they did it would not matter since the clients of SS all access the website through Cloudflare servers.
The UK government could approach the banning of SS in a few different ways each approach has its own problems and bypasses of us. Bellow are the possible approaches to banning SS in the UK:
1. They could try to do is stop Cloudflare from hosting SS but that would affect Cloudflare server's in the UK which can be quickly bypassed by just accessing a Cloudflare server which host's SS and is not in the UK.
2. They could do is try to block all the IPs associated with SS. Well if they do that then they will be blocking access to a lot of other sites as well. Doing this would be crazy and highly unlikely but if they did approach the problem in this manner first they would have to have sufficient technical understanding to propose this approach which I do not think is the case, second they would have to keep up with the SS IP changes that may occur on Cloudflare's side which is hard and expensive to implement especially when you take into account their inherent incompetence, and third they would risk blocking very key sites which have nothing to do with Suicide which undoubtedly cause an out cry against such an approach. Due to this I believe this is highly unlikely. Even if this does occur you would still be able to access SS using TOR, a proxy, or a VPN.
3. They could do is block all IPs associated with Cloudflare. Well this is similar to the 2 just more extreme. If they take this approach they will be blocking traffic to many key sites as many sites use Cloudflare. I believe this is even less likely than 2 but can be bypassed in the same way as 2.
4. They could also just block DNS requests for SS. That is to say force ISPs to refuse to resolve DNS requests for SS. This I believe is the most likely approach and is also the easiest to bypass. Currently most DNS requests are unencrypted and are sent to servers hosted by your ISP. In order to bypass this blocking mechanism all you have to do is first change your DNS server and second enable DNS over HTTPS(DoH) or DNS over TLS(DoT). DoH and DoT are newly emerging DNS standards which require DNS requests to be encrypted and allow for verification of DNS servers similar to how you verify website identity today. Thus when you utilize one of these standards your DNS request will be going to a non ISP server and more importantly will be encrypted and thus undecipherable by your ISP.
The DNS change and use of DoH or DoT are solutions to approaches 1 and 4. You can look up how to do this for you specific OS and browser online there will be a step by step guide to do so.
If the UK government is insane and decides to implement approaches 2 or 3(which is highly unlikely) than unfortunately your only options are to use TOR, a proxy, or a VPN. Each of these have their own issues. TOR is slow, VPNs are unsafe because for most VPNs they do not negotiate a TLS connection between you and the destination server thus all traffic you send to the destination server will be able to viewed by the VPN and proxies have a similar issue.
I hope this helps clarify the situation.