Camping in rmnp in October?

I'll be in the area for the first week of October and was planning on camping. Will it be too cold for tent camping? I can deal with 35 degree weather but that's about my threshold for a week.

In CO one can go as far into Autumn as they want.
All depends on your level of comfort and gear.
It'll be, lets say, crisp at night.
Depending on where your camping it can be breezy at night also.

But if you Climb hard during the day, got a good tent, the right bag and warm up via the fire with some hot beverages You'll be fine.

Moraine Park Campgrounds is open all year.

We scoped the camping out last weekend and it appears some of the sites away from the trees would get good sun to help dry out your gear.

I assume the toilet is open. It would be hard to dig in frozen soil, unless you're expected to pack it out?

I think my bag is good for 25 but i may be mistaken. I'm holding off on buyyin a tent just incase I decide to stay in a hostel or cabin. Is it possible to find a decent one of those for under 100 a night near climbing?

Oct is the Fall's high season Leaf peepers etc will be around. So cabin prices can still be pricey. You may try Valhalla resort just west of Estes but expect to pay around $100 wherever ya go. There are few cheaper motels but you get what you pay for there: not much. Remember we are talking a major tourist town at the gates to RMNP

then there's:
Colo Mtn school but their lodge is closed to the public but worth a call to them as maybe they can direct you better.

lonelyplanet.com/usa/colora…
Not sure whats goin on with this seems to be affiliated with Boulder Rock Club gym

Anywhere near Estes you are near climbing so don't sweat that.

October=Awesome. It may dip into the 30's at night but unless a cold front rolls thru that'll likely be it. I got married in October in Estes. It was sunny and 70's all week and then snowed on our wedding day. Best month to climb in CO in my opinion. You can get good days at almost all the non-alpine elevations. You should be fine with a 25 degree bag.