We got everything put back together again yesterday, and the panels all screwed in place to the frame, so there's no moving them now. They're much more solid, even with just a few screws per panel...it's really amazing how well that works! One of the window vents is like greenhouser's now though...very much "stuck" in place (our frame got bent a bit with all the panels being torn out, and there's just no way to straighten it now). The other roof vent is so loose I have to keep it on with clamps. So rather than deal with those vents, I think we're just going to keep them shut for the most part, and I'll buy some auto-vents to put in the top front panel above the door, and the bottom of the far-back panel, and I'll use the fans for exhaust (I saw some in the Charlie's catalog that aren't all that expensive). I won't be using the greenhouse when it's super-hot out anyways (everything should be out of there by the middle of June), so it shouldn't be too much of a problem. I can open the looser vent by hand if need be in May, but taking the insulation down at that time will probably help too. We also got a thermometer with a remote sensor this weekend, and set up the sensor in the greenhouse so we can start monitoring "normal" temperatures. It's pretty cool being able to tell the temperature in the greenhouse from my kitchen, and already this morning by 8am it was warmer than the outside temps by 4 degrees - on an overcast, snowy day (27 deg. outside, 34 in the greenhouse). A fun & useful gadget, to be sure, and we have no problem getting the remote signal in the house. We found an oil-filled electric heater this weekend as well...it was $40, but we figured the extra safety of not having semi-exposed heating coils or electrical was worth the cost. It has three levels, so I'll run it on the middle one (it will run more often, but not pull as much power), and it will work with a 14 gauge extension cord, so we'll get a 10 gauge for "extra" and it should be fine. The internal thermostat should be easy to set (same type as the one in my office). We picked up pavers from my MIL's house she didn't need anymore to create a solid base for the heater to sit on out there. I'm thinking of using foam insulation paneling all the way around the bottom of the walls about 1.5 ft. up (starting in the fountation), since bubble wrap is more expensive, and I won't be growing things that low anyways. Then I'll insulate the rest of the walls and the roof with bubble wrap, and hang a sheet of plastic inside the door. I'll get all that next Saturday, along with benches, fans, and a garden "sink" (that hooks up to a hose). Slowly but surely...all the seeds I planted this weekend should have a good home to grow out in by next Monday.

I think it a great idea to get a photographic neutral background and decide upon the paint colour for your room based upon your other fixed elements, e.g. flooring, new rug. Every white paint colour belongs to a Hue Family. In this selection, BM Cottonballs is the lightest (highest Value) but BM OC-151 is the most neutral (lowest Chroma). Creating the balance you want, between Value + Chroma is called nuance. All of these Whites are susceptible to changes in the quality of light available & their surroundings. Some people perceive the low Chroma whites from the Green-Yellow Hue Family as feeling more neutral.

Because you mentioned that drapery will interfere with the baseboard heater (AND because drapery shortened to end above with the heater will look like "high water pants"), I recommend inside mounted roller shades or blinds (one in each of the three upper windows), leaving the lower windows bare. Another option would be to frost the windows like these options: https://www.amazon.com/Decorative-Window-Frost/s?k=Decorative+Window+Frost

Agree with LIna. 6 ft. from a west facing window is too little for a cactus, even a barrel cactus. Ditto Opuntia. I only have one or two Opuntia, but they are grown outside on a SW lanai so they get bright Florida light -- and they do well.