Karen, Yes it can be done but need a few reminders.
If you have a 800 watt or higher crock pot this may start poping fuses due to the high voltage it will draw. It won't be so bad at 500 and under. Second do not leave the crock pot plugged in while batteries are not being charged. Excessive discharge will shorten life and being you have a Georgetown I am sure your batteries are a few hundred dollars.
The nice OPTION for invertors is that most will kill power if under a certain voltage. Now I have never tested this option but make sure to get it so in case you "Forget" you don't come back to dead batteries. Deep cycle batteries should not be run under 40% capacity left. It's hard on them after that.
Over all I don't think it's a bad idea at all.
2009 Dodge Ram Mega Cab 2500 6.7 cummins
2011 Forest River Cherokee 28BHKS