Here is my experience bro because I literally did what you are talking about but not an entire year. More like 3-4 months. I was on an IV oxy and Dilly binge for months. Shot 16mg of Dilly's at a time and 100 mg oxy at a time no problem and that didn't even get me blown and I could do that like every 5 seconds until I was out haha. Well after I went through the terrible pain of withdrawal and truly getting over acute and paws and becoming a real person again (which I might add is probably an impossible to understand feeling until you reach that point of sobriety again) I have been rehospitalized for major surgeries and avoided any and all narcotics for fear of addiction. However, I have mad respect for opiates now and their unbelievable power to control even the smartest and most sensible people such as myself. So when the pain got really really bad I asked for something for pain...doctor had a standard dose of 10mg norco. Dude I actually FELT that shit, made me talkative and warm! I couldn't believe it bro because I took 100mg of norco at a time or more (without killing my liver, luckily) and never even felt it. However, as mentioned above...your tolerance will SKYROCKET back up EXTREMELY FAST! I cannot stress enough HOW UNBELIEVABLY FAST it will go back up to a high level. In my experience, it was only 6 doses (4 hours apart for a total of 24 hours) that I already needed Percocet (oxy+tylenol) at 5mg. 3 doses of that and I already needed 10mg of Percocet (oxy+tylenol). 4 doses of that and I already decided to save up and pill and combine it for a total of 20mg percocet (oxy+tylenol) to feel good AND take away the pain. Now 20mg of perc (as long as I keep it to twice a day 12 hours apart) will still make me feel good, not great, but good. And because of the pain I had to be given IV Dilaudid (Pure pharmacy grade, it makes a big difference between pills and pharmacy grade please remember that) at .5 which didn't even touch me. That went to 1.0 that same night. That made me feel it a little bit. 1 to 2 days later, I was on 1.5, and 1 day after that I am now on 2.0.
Summary: Massive IV Oxy and Dilaudid Habit to sober, felt NORCO right off the bat, went to OXY and DILAUDID at standard maximum for hospitals within 1 week. So all in all, the answer is absolutely yes, but repeated use WILL skyrocket straight back to your standard tolerance (maybe a little under like in my situation, but only because I do not have access to more to continue to rocket jump it) so if you are ADDICTED I do NOT advice even testing the waters with some norco here and there, unless you make sure you have a limited supply and no way to get more quickly. In the interest of harm reduction, tell a good friend your plans and give them the drugs bro and let them dish them out to you just like the nurses do here for me. Because of my mad respect for these medications I am NOT pushing it past this point and ABSOLUTELY am not addicted again and will be able to stop instantly tomorrow upon discharge, but I was able to first-hand see how EASY IT IS TO BECOME ADDICTED AGAIN once you stop. Happy trails bro, happy trails. Peace from Riverside, California.