Looking back at some websites of loco hauled holiday trains back in 1984, there was a Bradford-Weymouth, a Leeds-Portsmouth, a Poole-Sheffield, a Nottingham-Paignton and a Penzance-Derby, all via Leicester. Some overnight holiday expresses too.
In 1988, there was a Poole-Nottingham train via Coventry, Nuneaton (where it reversed) and Leicester. An out and back Nottingham-Paignton 'Intercity Holidaymaker' ran until 1991 I believe, can't remember if in continued beyond then? Remember catching it in 1989 from Leicester to Taunton and back. Was great calling at Birmingham New Street without getting off and changing. Happy days!
Also, back in Virgin XC days, trains diverted off the NE-SW route when Derby-Birmingham was closed used to call at Leicester, whereas they don't now? Anyone know why this is so? Back in 2002 my parents went from Leicester to Exeter direct on a diverted service scheduled to stop at Leicester. Their first trip on a Voyager

Think the train was going to Penzance I seem to recall. I remember seeing Plymouth, Penzance, Bournemouth, Edinburgh and Aberdeen on the departure boards around 2002 quite well. The Sunday Leeds-Plymouth HST always used to call. I also remember a Derby-Poole as well which was Class 47 hauled.