There are about 48 swim sessions in the Oly Level 1 plan. 42 of those have sessions less than 2000 meters/yards, and I am confident you can finish that distance in 45 minutes. 6 of the sessions are 2500 meters/yards, and stronger swimmer will finish those sessions in 45 minutes. So, it depends on your swimming expertise, but even with those 6 sessions you can borrow 500 meters from the session and add it to a shorter sessions. For example, make a 1500 meter session 2000 meters and then the 2500 sessions 2000 for the week.