Main issue is broadcasting schedule Tuesday and Wednesday due to extensive  Champions League matches taking place all channels are full. Not sure if Sweden are running this week as well 

What is rider availability like for rescheduling first leg either Tuesday or Wednesday

What this cancellation may mean is that Ipswich have to run on a Monday instead of a Thursday not sure how much this will affect the crowd. So provisionally  Thursday Sheffield vs Leicester  Monday Leicester vs Sheffield  Thursday Leicester/Sheffield vs Ipswich  Monday Ipswich vs Leicester/Sheffield 

The big difference between speedway and stock car attendances is that Speedway relies on local support, whereas stock car racing has travelling fans from all over the country. I generally do about 30-40 stock car meetings a year, but my nearest track to home is about an hour away and some others are much further. A few years back I was in Cornwall one weekend and Scotland the next. Last night at Kings Lynn was the F1 World Final - the biggest stock car event of the season. As well as competitors from all over the UK, there were also drivers from New Zealand and Holland on both the big race grid and in the support events. Over 60 drivers had come over from Holland for the weekend, along with all their support teams and families. Travelling is far less of a risk as it is very rare that a meeting will be cancelled due to the weather, except if there is an extreme forecast and then it would be called of in advance, not 10 minutes before 'tapes up'. Just for the record, the £42 being quoted was the advance ticket price and they went off sale a week ago. The gate price was £48, and when I arrived at 12.30 (racing started at 5pm) there were big queues at the ticket office of people without advance tickets.

Almost correct as they are probably 2 of the top 3 attendance wise, but the biggest is the Unlimited Banger World Final which runs on a Saturday night in early October and despite a ticket price of £35 and increased car park fees of £4 instead of the usual £2, will more than likely sell out in advance.

Thanks for the update.