Yellowstone and GTNP with 27' RV

Hopefully this is the right place to ask, if not please let me know.

We are taking a trip in late august this year to Yellowstone, GTNP, and some surrounding areas just outside of GTNP. Is a 27 foot RV with a slide going to be easy enough to maneuver around the parks in? We are not bringing a toad, just the RV, and two kids. Our campsites are already booked and there should be no issues there, just curious on actual parking, sightseeing, etc. We are coming into the east entrance, and really just plan on sightseeing in the morning through afternoon then going to camp.

I'm used to driving RV's, I towed a 27' foot pontoon to and from the lake numerous times for years, and have experience driving fire engines, so I'm not overly concerned with the driving itself, more so just want some real world feedback on how much of a pain parking will be, and if theres any sites we will surely miss due to using an RV to get around. My biggest fear is being that A##hole blocking traffic.

Thank you,

** Edit- is there any advantage to taking a 25 foot RV? or is the difference negligible as far as parking and driving through the parks?