+1. I've already read probably 100 research papers this year in search of solutions to some technical problems, mostly while lying on bed with a tablet. I won't read as much without it.
Means I have to carry it in my jacket pocket or a side pocket on my combats but the bigger phones weren't comfortable in my trousers' top pocket anyway so for me at least the trade-off is well worth it.
If that isn't enough you might consider a tablet or e-reader instead of trying so hard to make existing options work.
You CAN convert to something like epub which is trivially reflowed and this is just fine for reading fiction but just isn't as pleasant and nicely formatted as a pdf.