Wondering if anyone has any experience/success with Comcast Xfinity X1 home DVR system on a large property with 2 separate buildings?

Wondering about distance limitations for the guest house from the main house and ability to have 2 TVs in the guest house on a single cable feed from the main house?

Ideal - Main house 2 TVs, one of which has the central DVR
Guest house 2 client TVs connected from the main house.

Currently there's a single RG11 between the main house and guest house, about 600'. (....and multi-strand fiber for the LAN).