Mixed Bag Smart Set Up (2 Houses) - Help Please?

[Tony Angelino]

Good afternoon, I have a mixed bag of a few different ‘smart’ items and for various reasons I have ended up with the following:

Hive Heating Home
Nest IQ Cam Outdoor Home
Various Smart Bulbs Home
Various Smart Plugs Home
Echo Dot Home

Next Heating Holiday Flat
Echo Dot Holiday Flat

I am also wanting to add the following:

External Camera x1 Holiday Flat
Couple of Smart Bulbs Holiday Flat (to turn on and off for security)
Leak Detection Holiday Flat
Smart Front Door Lock Holiday Flat

My objective is keeping an eye on the holiday flat remotely and not having to mess with keys if friends of family let it from us. My question is, is there any way to integrate all these things together or have I messed things up by having too much of a mixture of different brands and systems. Ideally I’d want to tailor alerts for the 2 different properties depending on the times etc. I have tried looking at IFTTT but the Next stuff doesn’t seem to work with this, I am far from an expert but I have a basic understanding of things so am happy to attempt if it’s possible.

Can anybody offer any advice please or should I bite the bullet and look to replacing some, obviously I would be keen to avoid this cost.
Thanks