WN does not interline with anybody. Thus, you are SOL if there is a cancellation or significant delay and there are no good WN options.

With high-level status on other carriers, you will usually be rebooked OA. That is a significant problem for WN business flyers who have important scheduling issues.

One thing to consider is that in the case of a cancellation or significant delay, you are entitled to a refund to your original form of payment (even on a WGA fare). While last minute tickets on other carriers will generally be more expensive, sometimes astronomically so, that is not always the case. There may be very cheap tickets on another carrier and in IRROPS handle it yourself. Cancel the WN booking and purchase the other carrier. So long as you keep a decent credit limit, it will all work out in the wash.

Alternatively, you could also do some shopping for travel insurance which has coverage kicking in at 3-4 hours at a decent level. That would provide additional cash which, when added to the WN ticket value gives you purchasing power OA.