Using wireless to record amps mic'd in another room


I was wondering if anybody had any idea of the amount of latency one could expect if they tried to use wireless to play guitar in one room (where the computer et al is) and another wireless on the mic's amp/cabinet?

I've tried using Bluetooth but the latency was ginormous. Well, huge by my extremely finicky standards. I was hoping if no computer was involved in the signal path until after the return from the amp/cab mic that it would be fairly minimal.
None at all on analogue, and minimal on most digital systems. The only thing is that most systems apply compression at the mic end, and then expansion at the other and sometimes the result is always a bit of compression you live with. Oddly - many of the cheap Chinese systems do NOT include the compander system, so might be even more transparent!
Why not buy two, identical modest passive DI boxes and link them with a mic cable. There is a sort of myth that this is how the DI box was invented. Even if there is no 'hole' between rooms you could run a mic cable in and out of windows. 50, even 100 mtrs, no problem. Even better if you can drive it at the guitar end with a buffered pedal.