We dealt with an infestation last year, you have my utmost sympathy 
You have made vast inroads into what sounds like it was a very heavy infestation but if you are still finding the odd one or two then you still have an infestation.
We used Bed Bugs UK and while they didn't completely solve the problem, we learned enough from them to finish the job ourselves. Don't bother with their passive monitors. It's £20 for a bit of corrugated cardboard. Our bugs never went near them. If you want to try something like that, there are instructions for making quite a posh one here:
www.winnipegbedbugheating.com/collect-a-bug-cardboard-bed-bug-monitor/
Or you can just put a piece of corrugated cardboard under the head end of your mattress and shine a torch down the holes to see if anything is hiding inside.
Keep the bed pulled away from the walls a few inches, and especially away from any windows with curtains or blinds. Also keep any other furniture a few inches away from the bed. This will discourage them from making harbourages elsewhere in the room.
Don't store anything under the bed, even in storage bags. I had a look at the SKUBB on Ikea's website. Not only do the bugs have no problem finding their way through a zip, but 'Your stored clothes and textiles stay fresh longer, as ventilation nets in the corners allow air to circulate.' Just because they have laid eggs on the outside, doesn't mean they haven't also laid eggs on the inside.
Anything that has been stored under or within a couple of feet of the bed should be completely sealed up in plastic until it can be washed, thrown away, carefully decontaminated (I'll cover this in my next post)or simply stored for 18 months (that's how long they can survive without feeding).
Get a roll of pallet wrap and some heavy duty rubbish bags (clear ones are less depressing to live with if they are going to be there for some time). You need at least two complete sealed layers of pallet wrap or you need to double bag things. Seal the bag by holding the neck and spinning it, then tie a knot. No 'bunny ears' - no gaps.
Leave the rest of the room undisturbed except for the laundry bin. Bugs are attracted to dirty laundry so it's important to keep this bagged up. Dissolving laundry bags are very helpful:
www.amazon.co.uk/Alina-Laundry-Water-Soluble-Plastic-Polythene/dp/B01N2VCY74/?tag=mumsnetforu03-21
You can keep adding items of laundry - squeeze the air out and give the top of the bag a good spin and twist each time - then tie a knot when it's full. You put the whole sealed bag in the washing machine and it splits open during the washing cycle.
Bugs can survive being hoovered up and the risk is that when they crawl out again they'll be in a different room and could start a new infestation in your sofa, office chair ... So you either need to remove the hoover bag and double bag it straight away while still in the bedroom or, because this will go through a lot of hoover bags, there is a trick you can do with a pair of tights. Make sure there are no ladders or holes in the toes:
www.mypmp.net/2016/05/19/recommend-this-method-to-bed-bug-afflicted-clients/
Any clothing that you have worn while de-infesting should also be changed straight away, while still in the room, to prevent spreading them round the house.
What eventually got rid of our last few stragglers was cimexa. It can be difficult to get hold of (I got it on ebay, shipped from the US), but they currently have it on Amazon:
www.amazon.co.uk/ROCKWELL-CXID032-CimeXa-Insecticide-Rockwell/dp/B0085HRWI8/?tag=mumsnetforu03-21
Don't over-apply, you just want a very light dusting around the bed joints, in amongst the fabric on your headboard and anywhere they are likely to walk through. You can also do the skirting boards, insides and underneath bedside tables etc. Don't worry about getting it everywhere they might possibly be, if they walk through it it will stick to them and kill them over a couple of days. They'll also take it back to where they are living and transfer it to their friends. We dusted a very light, continuous band around the edge of the bed, just where the sheet tucks under the mattress and repeated this each time we changed the sheets until we had seen no signs for 2 months.
Isopropyl alcohol will kill them on contact but it's highly flammable and the fumes are not great for you if you are spraying it around liberally. Soapy water will kill them almost as quickly. Also they are not hard bodied like fleas - you can squish them very easily with a gloved finger or a tissue.
Don't bother trying to do your own heat treatment (beyond putting things in a tumble dryer). You would need to seal every single tiny crack and crevice in the room or the bugs will just find their way out to escape the heat. You are also very unlikely to be able to get the whole space up to a high enough temperature for long enough. There will be cool spots underneath and inside objects and furniture and the bugs will just hide out there until it's safe to return.
I wouldn't bother with detector dogs either as they are not very reliable and it's likely to be quite pricey.
academic.oup.com/jee/article/107/6/2171/796348
The bedbugger forum is really helpful, as a PP said, unfortunately it appears to down for maintenance
bedbugger.com/
Good luck OP, with a bit of cimexa, a fuckton of single use plastic and just a bit more endurance (you're nearly there!) you can kill every one of these fuckers to death.