I've checked MySQL official documentation and haven't found answer on your question, then I googled for more information and found this article. So according this article it not possible to read from database, when there is no connection to master.
When you start a new server, it will try to get all the data it is
missing from the other group members. It will use the configured
access credentials and connect to another member fetching the missing
group transactions. During this period its state will be shown as
‘RECOVERING’, and you should not preform any action on this server
during this phase.
But google a bit more I found information that you in this article.
Note though that when a member leaves voluntarily, it first initiates
a dynamic group reconfiguration. This triggers a procedure, where all
members have to agree on the new view without the leaving server.
However, if a member leaves involuntarily (for example it has stopped
unexpectedly or the network connection is down) then the failure
detection mechanism realizes this fact and a reconfiguration of the
group is proposed, this one without the failed member. As mentioned
this requires agreement from the majority of servers in the group. If
the group is not able to reach agreement (for example it partitioned
in such a way that there is no majority of servers online), then the
system is not be able to dynamically change the configuration and as
such, blocks to prevent a split-brain situation. Ultimately, this
means that the administrator needs to step in and fix this.
That mean, that if your cluster loose one node it will work, but "loosed" node would be blocked to prevent a split-brain situation.
I think in your case better use standard Master-Slave replication, with this type of replication you'll able to read data from slave without any problems even without network link.
