I hiked about half of Adams last year in snowboard boots. I had my splitboard, but the morning snow was pretty icy and it was more efficient to boot it than skin. Made it almost to lunch counter before we started to skin, and that included 3 extra miles that the road was closed for snow. No complaints other than having to walk the 3 miles of road coming down, but that was because we did it all in a day.
I use strap-on crampons with my snowboard boots with no problems. Not sure if you can rent them at REI but that would be my first option. It might be worth buying some if you plan to do more backcountry riding. Check the Yard Sale forum or craigslist and you might find some for the same price as the rental.