I just stumbled across this new Cyclone 10 LP based FPGA board that is apparently due next month. It might make yet another reasonable and low cost P1V candidate board, though I've not tried the Cyclone 10 target yet in Quartus myself to see how well it fits - I think ozpropdev said it fits IIRC. It has 25k LE's which is a reasonably good indication a P1V would fit it nicely albeit using 66kB of blockRAM (same limitation as a DE0-nano). The board contains some flash and SDRAM too.
They also sell similar MAX10 based boards too but with less LE's (10M08/10M16 based).
Suits Arduino MKR form factor and a fraction smaller than Raspi Zero board.