I had an RPI4 8GB running weewx collecting data from a weather station and pubslishing it to various weather websites worldwide.
Then I discovered HA. As HAOS does not allow anything else to be running on the host, I had to go with HA Supervised (to be able to also get HACS etc.) With that setup, the only thing I could not easily use was the HACS Studio Code Server for editing. Not the end of the world. HAOS would allow all of that (including Studio Code Server editor).
I really love the RPI hardware and environment as well, and was facing the same issue as you. Therefore I bought an RPI5 - but then sat on it for a while because I could not decide how to easily upgrade and still be running everything I am running now - while I sadly saw people on all these forums talk about how it is much more bang for your buck to buy an NUC.
With regards to the other post about SSD compatibility issues, I dsagree - just like with anything else just be sure to buy compatible equipment, and be sure you have a strong power supply. For my RPI4 I have it plugged into and booting up from an Samsung T7 SSD (which even comes with the right cable) and it is MAGNITUDES faster than running anything off on a Micro SD card, you MUST use an SSD. What’s actually even slightly faster than an external SSD however, is an NVME.
Also I held back on pulling the trigger on upgrading to the RPI5 because I still wanted to use HAOS which is easier to maintain than the HA Supervised, but also still wanted command prompt access to the bare metal on it as well. I finally figured it out. I found on this forum someone figured out how to run HAOS on a VM on the RPI5, using the KVM/QEMU Virtual Machine Manager. You actually install Raspbian on the RPI5, install KVM, create a VM and install HAOS from a VM image onto the VM. And, to my great delight, I learned that a full backup of HA (I use the google drive backup) from HA Supervised, works perfectly when restored onto HAOS!!! That only took me about an hour! So as a bonus I was then able to happily install and use the HACS Studio Code editor.
So once I learned this then I went a little nuts and purchased this:
and here is how to assemble it:
Note, the display on the front only works if the RPI 5 is running a compatible OS (such as Raspbian, so that is no issue!). And I use RealVNC viewer to access it headless:
Note when you buy this to be sure to buy a good power supply and also the correct compatible NVME to ensure everything will work.
So also instead of putting weewx on the RPI5 as well, I left that on the RPI4 -
and I have some daemons running on the RPI4 to SSH into the RPI5 and populate additional statistics about the weather data transmissions into sensors on a dashboard I have in HAOS (using REST):
Note also, this KVM is unfortunately unable to take snapshots for backups - but what I do to create full backups occassionally is just boot up both RPI’s on SD Cards running Raspbian, then plug an SSD into each, and then just run the SD Card Copier app on each RPI to make an exact clone of the entire SSD onto a backup one.
Lastly, for statistics such as CPU temp and % used, on a VM there is no way to get those statistics from it’s host for some reason. So I have the RPI4 SSH into the bare metal RPI5 to get the information, then SSH into the HAOS instance and populate those statistics into the approriate sensors set up in HAOS for same (also, REST commands), every 5 seconds or so. Then I used chatgpt to figure out how to code the daemons on thew RPI4 such that they would continuously try to reconnect if the SSH connection is broken (by a network issue or an RPI reboot etc.).
I can’t find it now but there was a good post on this forum about how to install KVM/QEMU VM on RPI5 - and then how stand up the correct VM to then get the correct image to install HAOS onto that VM. (Then restore from your RPI4 backup)…
Thoughts? Good luck!