To set up an off grid system capable of running a fridge and a freezer is not cheap: A petrol generator may not be cheaper, but will definitely be simpler to set up.
I don't know how big your fridge/freezers are, but step one would be to see how much power they consume:
Get something similar to one of these. AliExpress will be much cheaper.
https://www.trademe.co.nz/a/marketpl...8?bof=BiWhSe3w
This will allow you to get a good handle on just how much power you are going to have to replace.
For a rough calculation's sake lets assume the two appliances will use 2KW a day.
And lets say that you have one KW of solar panels (3 or 4).
Lets say the fridge and freezer will run on free power from the solar panels during the day, and you have to store the other half of the power for the dark hours.
For simplicity's sake lets say thats 1KW during the day and 1KW during the night.
This is only for emergencies, so you can be harder on your batteries than a permanent off grid system would tend to be. So you are going to drain your lead acid gell battery to 50% every night. There's a bit of additional charging and losses I haven't covered, but you will get the picture.
So the battery will have to store twice the 1KW the fridge and freezer will draw. And a little bit more for losses
So you are looking (say a 12 volt system) at a 200 amp gel or agm battery
Then an inverter (say 2000watts minimum, a quality one will suck up the start up current, less so a cheap chinese one.
Then a charge controller (to look after the charging of the battery)
So minimum of:
$1000 for solar panels
$1600 for an inverter
$750 for that battery
$250 for a charge controller
Sub totol of $3600
Then some wires, joiners, fuses etc
Say 4K all up.
Then the skills to wire it all together.
Or a 3Kva Honda inverter generator at 5K...:o