Can the 2023 Land Rover Defender make a U-turn?

No. Needs more than 40 ft.

42.1ft curb to curb

Street width, feet

Street 40 feet curb to curb.

2023 Land Rover Defender 110 Standard AWD. Top view, to scale.

2023 Land Rover Defender: turning circle by trim, 40 ft street
Trim	Circle, ft	Margin	One move
110 Standard AWD	42.1	-2.1 ft	No
110 AWD	42.1	-2.1 ft	No
110 Standard (2023.5) AWD	42.1	-2.1 ft	No
90 S AWD	38	+2 ft	Yes
110 S (2023.5) AWD	42.1	-2.1 ft	No
110 S AWD	42.1	-2.1 ft	No
90 SE AWD	38	+2 ft	Yes
130 S AWD	42.1	-2.1 ft	No
90 X-Dynamic SE AWD	38	+2 ft	Yes
110 SE AWD	42.1	-2.1 ft	No
110 X-Dynamic SE (2023.5) AWD	42.1	-2.1 ft	No
110 X-Dynamic SE AWD	42.1	-2.1 ft	No
110 30th Anniversary Edition AWD	42.1	-2.1 ft	No
130 SE AWD	42.1	-2.1 ft	No
130 X-Dynamic SE AWD	42.1	-2.1 ft	No
130 First Edition AWD	42.1	-2.1 ft	No
90 X AWD	38	+2 ft	Yes
2023 Land Rover Defender 90 75th Anniversary Edition AWD	42.1	-2.1 ft	No
90 75th Edition AWD	38	+2 ft	Yes
110 X (2023.5) AWD	42.1	-2.1 ft	No
110 X AWD	42.1	-2.1 ft	No
110 75th Edition AWD	42.1	-2.1 ft	No
110 75th Limited Edition AWD	42.1	-2.1 ft	No
2023 Land Rover Defender 110 75th Anniversary Edition AWD	42.1	-2.1 ft	No
130 X AWD	42.1	-2.1 ft	No
90 V8 AWD	38	+2 ft	Yes
110 V8 (2023.5) AWD	42.1	-2.1 ft	No
110 V8 AWD	42.1	-2.1 ft	No
90 Carpathian Edition AWD	38	+2 ft	Yes
110 Carpathian Edition (2023.5) AWD	42.1	-2.1 ft	No
110 Carpathian Edition AWD	42.1	-2.1 ft	No
110 SE (2023.5) AWD	42.1	-2.1 ft	No
90 75th Limited Edition AWD	42.1	-2.1 ft	No
90 Carpathian Edition (2023.5) AWD	42.1	-2.1 ft	No
90 S (2023.5) AWD	42.1	-2.1 ft	No
90 SE (2023.5) AWD	42.1	-2.1 ft	No
90 V8 (2023.5) AWD	42.1	-2.1 ft	No
90 X (2023.5) AWD	42.1	-2.1 ft	No
90 X-Dynamic SE (2023.5) AWD	42.1	-2.1 ft	No

What this cannot tell you

Curb-to-curb turning circle as listed.

Mirrors and overhang need more room.