Reddit mentions of Regalo My Play Deluxe Extra Large Portable Play Yard Indoor and Outdoor, Bonus Kit, Includes Carry Case, Washable, Teal, 8-Panel

I don't LARP, but I have camped several times while pregnant and with a baby (kiddo is now a year old). There wasn't much that changed when pregnant (other than #2 below), but there are lots of little things that can make baby camping easier.

Things to consider/items that helped us:

1. Upgrade tent to a larger size. Our old one fit 2 - that wasn't going to cut it with a baby. We bought one big enough to stand in and one that is darker during the day (clutch for naps!)
   
2. Upgrade to a nicer air mattress. We used to use ultralight camping pads - that did NOT cut it when I was 7 months pregnant (such back pain), and sleeping basically on the ground after birth gave me clogged ducts since I was breastfeeding. OW. So a good air mattress is essential.
   
3. Pack n play. We tried just having her sleep between us one night. I didn't sleep a wink and it confused her too since she sleeps in a crib at home. So she now sleeps in a pack n play.
   
4. Heavy weight sleep sack. Even if it's warm during the day, nights are usually colder than your temp at home. Some people do baby sleeping bags, but a super heavy weight sleep sack did the trick for us. We did not camp when baby was still in a swaddle so can't speak to that. Bring warmer gear in general (hats, buntings, fleece jackets, etc.)
   
5. Bring a camping high chair. This is once baby is sitting/eating (~6 mo+). Something like this or this. Essential for meals and just generally containing baby if you need to be doing things around camp.
   
   The above were the absolute essentials for us. Other things I've seen be really successful for friends camping are a white noise machine (tent walls are thin if camp is noisy), giant play pens so you don't have to hold baby constantly, and as someone else mentioned, carrier or hiking packs.
   
   Last, go in flexible. Baby still has to nap, they're in an unfamiliar space, etc. Camping/LARPing post-baby will NOT be the same as it was before baby. And that's okay - just go in knowing that and you'll have a blast!

Setup a playard like this (if you have hard floors setup a playmat as well within the gated area. This type of setup gives them lots of room to play):
https://www.amazon.com/dp/B006NTY1HU/ref=cm_sw_em_r_mt_dp_U_eoiXCb43A4D11

Or use a playpen like this (I think this option is better for small spaces and/or you want to be able to move it from room to room easiest):
https://www.amazon.com/dp/B0725JZ9KQ/ref=cm_sw_em_r_mt_dp_U_vpiXCb5JR7RH8