but would it be possible to get a Backup upstream provider
Of course. Are you willing to (say) double the current amount for the next month for up to a year? There is no content without an exchange of monies. And a different provider will expect to be paid their U&C rates for that content, typically with a longer term contract. I have little doubt SD has done a quick survey of alternatives, but they are not going to be willing to be tied down until it is clear what happens next with the O company and their upstream content provider contracts. The lawyers will eventually come to some agreements on rebates/refunds for lack of service, but one cannot presume that it will be the number you want it to be. Typically it never is what you think you are owed, but it is the number you can sort of live with, even with the bad taste in your mouth from the experience.
The best of the bad alternatives is likely for SD to refund you for not being able to deliver service as contracted for this month, and (perhaps) lower the monthly fee for future months with an abbreviated offering at this time if they do not have a clear expectation of a date for resolution(*). But after the existing month, you should not renew if the service at the price offered is not to your liking (don't buy futures/promises). Once the contract issues are resolved, make a new decision as to whether to newly subscribe. That is as much true for the Premium TV service as for any other subscription service (cancel your cable/satellite/ISP/Moble contract if the price is higher than the value it offers you today).
(*) I happen think that Dish, and Charter, and .... should also lower their monthly rate during contract blackouts. In some cases they will, if asked, offer a discount. It should happen automatically.