it is insanely cumbersome to achieve this, but it is doable and once set up, it runs like a dream. I've got it on a T480s (F40), T420s (Arch), MBP 2010 (Debian 12) and MBPr 2012 (F39), all with encrypted LVM + btrfs, some with a swap subvolume, some with a separate swap partition outside of LVM (waaay faster boot, no decrypt prompt - dreamboat!)

basically you have to allocate a swap file, subvolume, or partition that's RAM * 1.5 (on account of zram) but don't add it to fstab. then you have to dick around with systemd scripts that turn off zram and activate swap on suspend and do the reverse on resume. then, dracut or mkinitcpio have to be set up to use the resume funcionality (when coldbooting it looks for the resume swap file and if present restores this instead of booting). also, there's adding kernel switches to systemd-boot or GRUB to utilise resume.

edit: oh yeah, also taming selinux to allow you to write to said swap.

now that would be just enabling hibernation, but I don't like explicitly activating suspend or hibernate, I wan't it to hibernate after I've left it in suspend for a while; I've set it to 60 mins. that way I don't have to think about it, just use my laptop like it's actually 2024.

also, since you're now coldbooting several times per day, it's essential that this process is as fast and jerkless as possible, hence systemd-boot with all pauses and timeouts set to zero.

the steps involved depend on your distro, I've made it work with Fedora, Arch and Debian. Here's a good primer so take it from there and use the arch wiki and experiment.