Missing climbing is almost unavoidable: work, family, weather, conditions, backing off the first pitch are all likely to happen at one point or another. The way to decide on what sort of workout to impose when this happens is to look at what you have access to and knowing that along with having an objective assessment of your strengths and weakness you can move to the next step. If you are interested in big routes on big mountains your default workout should aways be to build aerobic capacity. YOU CAN NEVER HAVE TOO MUCH AEROBIC CAPACITY. And you can train this in alost any weather. This is assuming you have necessary technical skills/specific strength needed for the route of your dreams (your short term goal). If you are in your Transition or Base phase then basic strength may be most important. If basic strength is already high and/or you at a more specific period of training them maybe it is the hang board or climbing gym workout. The top alpinists I work(ed) with spend up to 15 hours a week running or ski touring in the mountains. Enough so that they can hang with good ultra runner in training runs. They understand that the aerobic base underlies all the other training.
This is as close as I can come to a general recommendation
Hope this helps,