I too have been looking for this,
I am not willing to pay the £25 a month for 3 months then £33.99 there after. You work that out over the remaining F1 season that's £176.97 for 6 months, compared too £198 for 9months. Average that out and it's £29.49 a month when the original deal is £22 a month for 9 months. I'd rather pay the £22 a month for 9 months from the start of the season (4th July 2020 Austria) than pay that. It would take you through to the start of next season ready for the next season deal which would be perfect!
I am not willing to pay the £25 a month for 3 months then £33.99 there after.
It's unlikely you will have to play £34/month after three months. If you cancel your subscription in the last 30 days, you will most likely get an offer to stay (£20/£25 a month). Also given that in two to three months time it will be the new football season there are likely to be offers. And if worst comes to worst, you could just get a £25 month pass from Currys and await the next offer.
Also should there be a second wave of Covid-19 and the season is abandoned, it may be better to just pay one month at a time. You are not obliged to keep the pass going for three months, you can cancel before end of first or second month.