Hi Jack and Betsy,
I have been to both. I have not been to the LV RV Resort so can't comment on that.
Here's my recommendation based on the fact you will also have very young grandchildren accompany you sometimes and that you and your wife ride bikes/trikes.
It sounds like Oasis would be a better choice for you if you plan to stay for about 10 days. While it is a little farther from the strip it would be a short drive anyway and is easy to find. As for the grounds they are more open, grassier, more like an RV resort. Since it not so enclosed by towering casinos it is my opinion it was also quieter. Here's their website link:
http://www.oasislasvegasrvresort.com/
The night we stayed at Circus Circus KOA (Circusland) there were some revelers who got a little loud but that's because they were all together very close to our site. Not beyond quiet time, but noisy up to that point. But we didn't care too much since it was only a stopover prior to going to 1000Trails. The Circus Circus KOA is in the Casino's parking lot but closed off to the public. But the staff does make a great effort to keep it secure and slow and quiet. There is very little grass and we never saw bicycles around the area, but being right next to the casino the RV Park caters to casino go-ers. There are moving sidewalks to Circus Circus, then it would be a long walk to get to Caesar's. Look for the site starting at
www.KOA.com.
You'd probably end up driving from either RV Resort to Caesar's because of the distance unless you are in good shape, have good walking shoes and allow plenty of time to get from place to place. In your wedding duds you might want to drive. If it's at all warm (and should be) you'll want to drive.
However if casino hopping is what you end up wanting to do more and you also find that the May heat prevents the bike/trike rides then Circus Circus becomes the place to stay since it is ON the strip.
If you haven't been there plan a trip to Hoover Dam. It is a short jaunt to an impressive site. Allow all day and take your time. There are tours, eateries, some walking and a good parking structure. My Ford F-250 4x4 fit under there with no problem and with my antenna my truck is about 7' 5" tall. I recommend don't go on a weekend!
Maybe you'll stay 5 days in one resort and 5 days in the other.
Have fun.