Refrigerator is a constant draw plan on 10 to 15 AH day. Lights can be a big draw, calculate draw and number of hours used. Water pump is not a big deal, draws a lot, but only briefly. HW heater can use an AH or 2 per day. HEATER can be the big bird! If you use heater 4 hours, that's 35 AH. If you use LED lighting, for 15 AH per day (just a swag for planning )you're looking at 75 AH per day.
A 100 watt panel in 5 hrs. of good sun will get you 20-25 AH or so. 300 watts would do the trick if every day were sunny, and your panels were in the sun !!
I have 120 watts permanently mounted, and a 100 watt portable. We just returned from a month in the north-east, mostly dry camping some with elect. I had to use the generator once (first time this year). Constant problem is getting sun. Most campgrounds are well shaded, and even with the portable, it was not possible to keep up with the usage.
This is just my experience, but should give you a good way to see what you will need.
Good Luck,
Doug