Postgres 14

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table bin_data (bin_range int8range);

CREATE TABLE

insert into bin_data (bin_range) values
  ('[1,8)'), ('[8,9)'),
  ('[10,20)'), ('[15,30)'),
  ('[35,40)'), ('[40,50)'),
  ('[50,60)'), ('[60,70)')

INSERT 0 8

Select range_agg(b.r)
From (
  Select int8range(lower(bin_range)+1, upper(bin_range)+5) as r 
  From bin_data) as b;

range_agg

{[2,35),[36,75)}

SELECT 1