Dale, since you are talking about a trickle charger, I'm assuming you have some access to power where you park.
Even if it is a 15-20 amp power receptacle, you can maintain your batteries safely. Make sure you have EVERYTHING in the coach turned off. Unplug things like a satellite receiver that stay hot even when turned off. Make sure all the air conditioners are off along with the hot water heater, etc.
Since you have minimized your electrical usage, next you need to set your inverter/charger to the lowest shore power setting you can. Depending on the brand and model, this could be 5-10-15 amps. You really need to understand the setting on the inverter panel so that it recognizes the limited availability of shore power outlet.
This arrangement will use your normal charging system to maintain your house batteries. I believe you have a Monarch and that model may not charge your chassis (engine) batteries while on shore power. Many folks have added a simple system to keep the chassis batteries charged. You could also just use a jumper cable to connect both battery banks together during extended storage.
2006 Monaco Signature -45' Castle IV
All-Electric, Cummins ISX-600