The rule of thumb for warm white LEDs is they consume 1/8th to 1/10th as much power as an incandescent bulb when you cluster all your LEDs into one spot. The most used incandescent in trailers is the 1.5 to 1.8 Amp, 18-22 watt 1156 bulb, so, if you replace an 1156 bulb with a 40 LED, 2watt LED tubular bulb replacement.
These 5M, 300 LED strip lights burn around 14 watts, the equivalent of 7 1156 bulbs, but allows you to distribute that light a little more evenly around the trailer than 7 single-point lights can, a fact borne out by the judicious placement of 30 watts of warm-white LEDs throughout our 19' Scamp 5th Wheel.
Back to our 5M lengths of LED strip lights. Having just arrived today and been tested just before I posted this, I'll buy another 5M strip and install them in our 14.5' Surfside
tear-down and make-over project trailer. I'm planning to use about 7 meters of the stuff, cut into lengths (something that's easy to do with the non-waterproof version, but not the vinyl-encapsulated waterproof ones) and installed under the cabinets over our kitchen counter, front dinette, and in the dome of our ceiling, these lights will form the basis of our trailer's lighting system. Add in another 5 or 6 LED "spot" reading lights, and our trailer will burn 30-35 watts when they're all turned on, considerably less than just two incandescent bulbs but more than enough to look like the bright light at the end of the tunnel that turns out to be an oncoming fiberglass trailer project. ;-)