Many of the manufacturer websites will give lengths of the boat with the motor down and/or with the tongue folded. I'm only listing Skeeter as an example because I know it's handy, but I've seen many of them give this info. https://skeeterboats.com/Skeeter-Boat.php?id=50
Length on Trailer (Towing Length) 27' 8"
Length on Trailer (with Motor in Towing Position and Swing-Away Tongue Folded) 25' 2"
Length on Trailer w/Motor Trimmed Vertical w/Swing-Away Tongue Folded (shortest length) 24' 4"
Width on Trailer 101"
Boat Length 20' 11"