For actual active fermentation I keep US-05 in the low to mid 60s and have always had great results. I've never tried any higher than that, so I can't speak to the 70 degree range.
I would be very comfortable moving a carboy to a room with temps in the 80s once active fermentation is complete. I actually used to do that every now and again when I had a ferm chamber that only held one carboy. Generally speaking, fermentation temperature control is most important early. Now there's the aging temperature question and I'm pretty sure higher temps accelerate staling, oxidation, and the like, but I doubt a couple weeks will make a huge difference. If it were me, I'd just bottle it or keg it at that point, but there are plenty of threads on that topic and I'll assume you've read them and made your choice.