Temporary multiple locations - which plan setup to use

We are in the process of moving into a new house. I want to protect both locations. I have a subscription for my current location and a base station there. I bought a new base station and new alarm system for the new house. Once installed the two systems will both be running for about 1.5 months after which I will dismantle the system at the old house. My current subscription is set to yearly payment and due to renew a month before I will need to stop the subscription for the old house. What is my most efficient and cost effective way to run both systems for 1.5 months so that after that I have only one subscription left? Thanks in advance.