i think 35 lbs should kill a dear handily. That said, I also think that if you bump up your routine, that 40=50 lbs should be no problem. use resistance bands and draw your bow at least 5 times a day. Crank it up one crank every coupla day. you will be fine, the only way to get stronger is through repetition and increasing weight!! then when you go down to 40 it will feel like nothing. And remember to stretch and stay nimble in the stand. Being warmed up is important, you will shoot better, as well as be able to pull it back. trust me it gets cold up here lol
Good luck