I bought a starting battery as well. (DL+ 12v 60Ah Dual Purpose 1000CCA Starter Battery Plus Deep Cycle Performance)
I'm not a tournament guy, when it starts getting too cold. I pack it in. My 175 TXW will live in a heated workshop for the winter (at least for the next few years.)
My only concern is charging, as I've always used AGM's in just about everything and have used battery maintainers with auto desulfation with excellent results. Most batteries lasting 10 years or so.
I bought a Minn Kota 3 bank on board charger with a LifePo4 setting. (Minn Kota MK-3300 PCL Precision On-Board Charger)
I'm just learning Lithium (unless you count RC Aircraft.) The liFepo4's don't appear to have a float voltage, and apparently the on board BSM's take care of cell balancing internally.
How do you manage a storage charge, when the boat is dormant for 3-4 months?