I am planning a trip for August, from the UK and then taking 2 weeks to travel down to Croatia. We are then flying back from Croatia to the UK.

From research I think that we can leave from our local train station, head to London and then on the eurostar to Paris and that is fine on our interrail ticket, as long as it is on one travel day.

When we come back, we are flying from Croatia to Luton and then need to travel back to Cornwall. Again it will be in one day so can we use our Interrail pass to get from the airport to London,  change trains and then down to Cornwall. I think we can but wanted to check