I certainly wouldn't trust new wifi. If it's being shared amongst 50 flats then it'll be hitting its bandwidth limits (which are fairly low) pretty quickly. They also tend to not use the best equipment in these sorts of things. Also, higher likelihood that your PC could be compromised if on the network with a lot of other computers. Best you can do is try it but I'd see what you can do to get another connection just in case.

On ENC, if you watch the "My Cat from Hell" show (I binge watched it, don't judge me) you quickly learn there are two types of cats - shrub dwellers and tree climbers. Sounds like she's one of the former.