How much harder are your projects than your on sighting grade.
Generally second or third. I'm not really into serious projecting - too many places to go and see and routes to try. My three 6c+ redpoints so far went in three, five and three goes.
If your local wall has a figure-of-8 circuit board, you could always put away 30mins a session to top end PE but trying to work and then lap the next hardest thing that you can't do yet. I expect that would be in the order of 7a/+ maybe?
If there is a long(ish), powerful and slightly gymnastic bouldering traverse (a la weedkiller) at a crag near to you, it may be worth trying to work on that on the evenings after work. It did wonders for me.
rowing/kayaking/paddling (i remember a very enjoyable river trip in the jura! so many castors...)