Given a travel related situation, and given a specific question about the situation, summarize the question into a title

[Q]: I am non-EU family member married to a Romanian citizen. I am currently residing in Romania and I have temporary residence card here. As Romania is in EU but not in Schengen area, can we travel together visa-free within EU and Schengen countries ?

[A]: Non-EU family member traveling to Schengen countries?


[Q]: Background

I've recently entered a relationship with a person from Canada. Part of that commitment involves visiting frequently throughout the year; this commonly involves me driving to pick her up, as opposed to flying to save cost, so she can stay with me in the US. She's planning on coming up to visit again for the entirety of the Summer (four to five months).

Extra information in case it has any impact:  


She is 20 years old.
She is a third-year university student and is committed to her program for another two years.
She has visited the US three times already this year. Twice to visit me (~five weeks in total); once to visit her friend (five days).
We've both lived in our respective countries all our lives.
I've only stayed in Canada with her for a few days at a time.

My Knowledge
Feel free to edit this information if any of it is misleading/incorrect.

The 180-day limitation mentioned in these threads [ 1 ][ 2 ] are for people who visit in one consecutive stay; not for totaling 180 days in the year.
She will be considered a resident alien of the US if she crosses the 183-day mathematical formula, as noted on this AmericanLaw website:


  A foreign national will meet the Substantial Presence Test if he or she is present in the United States for 31 days in the current year and the sum of the following:  
  
  
sum of the days present in the United States in the current year,  
one-third of the number of days present in the first preceding year,  
one sixth of the days present in the second preceding year equals or exceeds 183 days.

  
  If a Canadian meets the Substantial Presence Test but is ineligible to meet the Closer Connection Exception (i.e. since he or she is present in the United States for more than 183 days in the current year), he or she will be considered to be a resident alien of the United States. Resident aliens are taxed on worldwide income in the same manner as United States citizens.


Question

Are there any common limitations, mainly regarding stay durations or frequencies, that could make further visits throughout the year difficult or impossible?


Also, I fully understand that a visitation could be rejected for many reasons and that there's no guarantees regardless of how long of stay. I'm simply trying to avoid breaking any rules or missing any legal obligations that can come up from this international relationship. This is all foreign to me— pun was most certainly intended.

[A]: What visitation limitations can come from a Canadian visiting the US for too long in the year?


[Q]: My problem: I recently booked a business trip about three months out, noticing slightly too late that there's a huge event (Formula 1 race) happening in town the previous weekend and all the remotely convenient and/or comfortable hotels are asking crazy rates (US$500+).

The usual rule of thumb of booking flights and hotels is the earlier the better, since prices usually go up but rarely come down.  In this case, though, I have a sneaky suspicion that hotels may be demanding too much and there may be a fire sale of unsold inventory right before the event.

So: Do hotel prices generally go down right before big events? Bonus points for answers with data instead of just speculation.

(Note: this question has been edited, as I'm more interested in the general question above than the specifics of my situation.)

Interim answer 1: I've followed simbabque's answer and booked a mildly inconvenient and mildly crappy but fully cancellable and not crazy expensive hotel to cover my ass, and will check & report back on the hotel situation before arrival.

Interim answer 2: Idly poking around, I noticed that a big chain hotel near the office that had previously been 100% full had a room free for all three nights at our normal corporate rate (~US$120).  Booked!  But I'll still check before arrival and report back for science.

Very overdue final update: I didn't do a very thorough check because work, but a casual browse on Google Hotels did show a bunch of hotels offering rooms at less stratospheric prices (under $300). YMMV.

[A]:
When should I book my hotel if prices are inflated due to a major event?


