I've been working with a mixer over the last 7 years who uses a "Fun Box" - a VR Field with an extra receiver, IFB transmitter, antenna mast with 2 sharkfins, and an extra empty channel for more flexibility. It's powered off of two older NP1's and we change it every hour and a half. He put the whole thing together in a really nice custom wooden frame and got a custom 8 channel snake made with 5 pin xlr connectors.
I made a V2 of my own using a small rack case, a Venue 2, SRb, IFB transmitter, M-216 (as a backup only) and ran 3 channels of Cat5, giving me 12 channels all together. Powered off the Hi-Q batteries, the box could run 4-4.5 hours.
I think "dropping the bag" will become much more prevalent in the near future but it comes with its disadvantages as well that some people might not realize. On a fast-paced narrative production, your utility needs to be on top of it, making sure battery changes happen on time, moving the box/bag out of the shot/away from focus pullers and teradek transmitters (been a big problem on our show), being ready to move it so a light can go where it is, covering the cable so people don't trip, making sure scissor lifts don't cross your hundreds of feet of cable and damage a line. Not to mention not being able to monitor/control the receivers unless using Dante and some Netgear stuff. I took my 3 channels of Cat5 and wrapped them in Techflex and it became one giant unwieldy cable which I hated AND it was super slippery and people were tripping on it. Also, if it's just a bag rig with no mast, your antennas are much lower to the ground which is worse for reception. Lot's of things to consider, so don't put all your eggs in one basket.
Towards the end of my run on that show, we still used the Fun Box, but kept it right next to the cart, and only extended it out when we needed to. We often had better RF when we weren't so close to all the cameras, focus pullers, and walkies. Walkie hits were a big problem sometimes. If you need to be far away from set (which seems likely to become normal) and/or the show likes to shoot in tight spaces that are hard to get to, then this is the way. For me, I built everything back into my cart. If I need to run antennas out, I use the Ultraflex LMR 240 which someone recommended on this site. It's amazing. Skinny, not stiff, and very low loss. Check it out. If I needed to get really crazy, I can always drop my bag rig and pull the cat5 off the truck. That would give me more distance and better reception of IFB and comms. Food for thought.