I'd seriously consider going to a counter top stove instead of the hot plate. The stove will be cheaper than adding enough battery and solar to feed just the hot plate.
I have solar on my boat for the fridge and it keeps up nicely on sunny days and hits "float" by noon. On cloudy days it takes most of the day and still keeps up with the fridge, radios and lighting.
Converting to AC and cooking, Mr Coffee or a microwave really draw a lot of power when in use.
I have a friend who has a bigger boat and put solar all over because mine worked so nice and he still has "low" batteries quite often (4 X 4D's). He was perplexed and bribed me with a few beers to take a look. We'll the problem was he (his wife) uses the microwave a lot, her hair dryer daily, a large electric coffee maker, water heater and even an electric can opener as well as charging laptops and phones. When I explained how much he was using compared to what he could get from his two solar arrays, one at 400 and another at 360 I think. Anyway we took a long look at what the trouble was with his gen set and fixed it instead of adding more solar.
Solar is great but be sure it suits your actual needs.
Dave Neptune