Are there any electrical outlets in the sleepers?

The inverter will be the best bet because the sleeper bunks have cigarette lighter plugs in them for just this purpose. At least every truck I ever saw had them.

 

a small fridge...an actual fridge. I wouldn't use anything less than a 2000 watt inverter for an actual fridge. I would not want to be worrying about power overloads or shorts because i used too small of an inverter. My motto... better safe than sorry. And as far as the laptop a 400 watt inverter is plenty big for a laptop.

 

1.) I don't know where people get the misconception inverters are not allowed in trucks. Every driver I've talked to has one, across many companies.

2) Anything that needs to be plugged into the Cigarette lighter"plugs" is worthless just about as worthless as the "plugs" themselves.

3) In our 2018 Freightliner Coronado SD - we run 3,000 watt inverter. That runs all the time, connected to the batteries. (powers 2 laptops, full time power to the refrigerator, coffee pot & whatever "appliance" I'm using at the moment from a Microwave to a Electric Skillet, etc.)

4. As for a "truck fridge" - we use the "College/dorm" size refrigerators you can get for about $200 at Walmart

 

I drive for Swift and have had 2 trucks. Both had 1800 watt inverters installed in them. I have a small microwave, a coffee pot, a toaster and a 54 quart freezer. I have not had any problems. The freezer runs all the time, but I don't run more than one of the other appliances, along with the freezer, at any one time. I have had no problems.
Any inverter with enough wattage to run a blender will not plug into a 12 Volt cigarette lighter type socket. Simply not enough power available. Any inverter that size will have to be wired directly into the battery bank.