In reply to wurzelinzummerset:
There will always be a readjustment phase going from indoors to outdoors, so bear in mind that any improvements may take a month or two from the start of the outdoor season to make themselves felt (my most productive times of year are usually May-June, when im still strong from the winter but have got the rock mileage up enough to be able to apply it well).
In terms of potential improvement, anything from zero grades to potentially a half dozen or so depending on whether your weaknesses are the things which are easily trainable indoors, whether you train intelligently to target those weaknesses, how many of your sessions are good goal-focussed ones, whether you manage to avoid injuries whilst training, and a whole host of other variables including what style of climbing (onsight or redpoint) and how much time you are prepared to invest (either in projecting days or in failed onsight attempts) outdoors to realise the goal next year.