Do you know the model of the Freesat boxes you're looking at? The new 2022 models AFAIK now also use 2x Wideband channels, the same as Sky Q.
If it's a slightly older model box then they still use the old universal LNB type. In which case assuming your dish is Sky's own supplied one, all you should have to do is swap out the LNB for a Hybrid one if you want to retain the option of having Sky Q again in the future. You can get LNBs which have 2x Wideband and anywhere from 2-6x Universal connections for your Freesat box feeds.
However if both Freesat boxes require the new wideband, it's a little more complicated. I'm not aware of any LNB with more than 2x Wideband outputs... So the option would be either having 2 satelitte dishes, or look into putting a splitter on and seeing if that works. From having a quick read online I found a thread (
here) where someone has asked about putting a splitter on the runs. If this works you could get a splitter on each of the 2x Wideband channels, giving you the 4 runs needed to go to your 2x Freesat boxes.
Someone else may be more clued up and correct me, or provide an easier solution. But from my own limited knowledge this is what I'd be trying myself
