You could also keep the rest at two days, but increase the benefit of the sessions you do have. This might suit you more as you have allready said you won't be getting to the wall load more than currently.
You could use a different training process parhaps, eg trying CIR as its called in "The Self Coached Climber".
This is when you climb a number of problems at the same gradeish, with a standard rest time (Continuouse Intensity Repertitions). Over time you increase the number of probs you can do in one session. Eg if you can nail 6b first go on a good day, then doing 5c or 6a probs x10 with eg 2 mins rest in between, increasing to x20 over a few weeks. This results in a great increase in fitness without pushing the maximium effort injury zone. I think this can give you great fitness to use either as a base for some more focused top end intensity training, or to use for that elusive red curcuit blitz.
I have used this a couple of times a week and really noticed a difference in what I could do, at a level above the grade of any individual prob I was training on, if that make sense...