Hard to say. This is pretty low profile. My guess is probably closer to 150 miles. There are a lot of lightning and Rivian owners towing smaller lower profile trailers with their EV trucks. Many see closer to 200 miles towing the smaller profile trailers and tear drops..........and from what I've seen, you'll be stopping every 100mi or so, for Lord knows how long, to recharge, paying a yet to be determined price for the electricity.
If Rivian actually builds the bigger pack they had ousted that some people have ordered and are waiting for I think it would tow something like this 200 miles without the assisted axle of the trailer and probably 300 miles with. I don’t think they are doing that till 4th quarter 2023 though.
Bigger batteries so probably 40 to 50 minute charges though. And of course the trailer traction battery would have to be charged as well. Probably in a campground.
All fast chargers have their prices clearly marked on their apps. There are no unknown prices.