My O2 don't drop below 90 and I'd usually 94-96 even exercising in therapy. The congestion makes it a little hard to breath deep but the O2 stays high.
Actually quit smoking before we knew I was having heart problems, but only smoked about 2 packs a week, mostly when driving by myself or when I got writers block.
When the hip was bothering me I ran out and didn't feel like running to the gas station so after about 5 days I decided I didn't need them.
Got an echocardiogram in a couple weeks and if it shows good I should be in good shape when things get healed.
Drs say I should be good to go this summer, 3 of my trips I just need to show up with bedding and such because Norton will be there with the wagon and has more gear than me anyway. The big one will be the Muster and the kids said they'd help load and unload on this end if need be and should be help on the other end. I think the 2 from Wisconsin would help. Once loaded and unloaded I should be fine, Gopher Grease may come and if he does well drive his pickup and use him for the heavy work.