Ok so its been arctic for a couple of days but a Hot water systems costs massively more than a standard system.
On an ordinary day is the end clean result worth the increased equipment and running costs? and are there other manufacturers than Ionics with Thermo Pure?
In terms of increased real world profit, not just gaining back a few lost days due to frost, that's still down to you & your own efforts with it's promotion/marketing.
A perfect result is acheived with cold wfp, so you can't improve on perfect.
IMO, for most I would imagine it's a balance between the advantages hot can give you in cold weather & your own personal working conditions being more comfortable in the cold.
So, based on increased profit only= who knows?
or
Based on the last paragraph= why not, if you can afford it & you want one, treat yourself. You don't have to justify it to anyone but yourself & your circumstances.
Tony