I fixed our prices again with Octopus in September, before our old fix expired.
We are in credit, and the fix means that, given our historic consumption over a year, our monthly payment will more than suffice to cover any likely bills, even if we have a very harsh winter.
Indeed, next year, we may take some of the account credit and have a break somewhere.
I have found Octopus pretty good to deal with since switching from OVO.
I always phone Octopus - you can stipulate more details and cutover times and dates etc when changing tariffs - and I have been able to forward lock in a change at a future date using a current tariff that would no longer be available at the time of change. Pleasantly surprised I could do that.
Fixes seem a bit cheaper than a few weeks ago.
Can probably save close to 4p/kWh for electricity with Outfox.
Actually 4.84p/kWh as the higher Ovo quote didn’t include VAT!
Bloody ridiculous.
It’s always a gamble when to fix and it may have paid off for you. 
My GCH is costing on average about 11p per hour over the last few days. It’s on 24/7 so the fabric of the house is warm.
The gas is about 6.37 + VAT.
It was maybe another 1p cheaper when @Count.d suggested Outfox a few months ago!
Must jump soon as nearly 5p/kWh is a big saving with high electricity usage.